Hong Kong (CNN) The young protesters who have thronged Hong Kong's streets for three months warned the city's leaders from the beginning : "If we burn, you burn with us."

That threat seemed all the more real on Saturday, as black smoke poured into the sky from a huge bonfire set by protesters following violent clashes with police outside the city's legislature. Petrol bombs and bricks were thrown during that standoff, as police replied by firing a water cannon and round after round of tear gas.

Violence continued late into the night, as police officers surrounded by protesters let off warning shots and riot cops were later seen charging into a subway station and attacking alleged protesters on a train. On Sunday, it was protesters who targeted the subway, shutting down and vandalizing several stations after an hours-long standoff which paralyzed transport to and from the city's airport.

As the violence continues to escalate, Hong Kong's leaders have made clear they will not negotiate on any of the movement's key demands, despite calling for "dialogue."

A flight attendant sprints past a burning barricade in Tung Chung on the way to Hong Kong international airport during protests on September 1, 2019.

The government's message to protesters seems to be go home empty-handed or risk a major crackdown -- which, at its most extreme, could involve the military.

But there are signs that gamble could backfire. Protesters have shown no hesitation to causing disruption to the city's economy and daily life.

As the mood becomes more nihilistic and angry, some may even welcome a crackdown.

The mood is shifting

The past week has seen a clear escalation in how the authorities handled the protests.

On Friday, several leading pro-democracy activists and politicians were arrested and charged with a variety of offenses, including the vaguely worded "Inciting others to participate in an unlawful assembly," which carries a maximum five-year jail term, in what appears to have been an attempt to fulfill an impossible task, taking the head off a leaderless movement.

Also on Friday, a rally and march planned by the Civil Human Rights Front (CHRF), the group which arranged previous mass peaceful protests attended by hundreds of thousands of people, was banned by police. Although CHRF represents the moderate, non-violent wing of the protests, and has demonstrated support from a broad swath of Hong Kong society, police had no intention of risking an escalation.

That escalation came regardless. Demonstrators took to the streets on Saturday in wildcat demonstrations that eventually coalesced around the legislature, where an hours-long battle broke out between more extreme protesters and police, and spread to other parts of the city. Protesters threw petrol bombs and bricks at police, and aimed laser pointers at them.

Photos: Hong Kong unrest A riot policeman sprays pepper spray at a man as they disperse a crowd during a demonstration against "parallel traders" who buy goods in Hong Kong to resell in mainland China on Sunday, January 5. Hide Caption 1 of 160 Photos: Hong Kong unrest Pro-democracy supporters hold placards as they take part in a New Year's Day rally on Wednesday, January 1 in Hong Kong. Hide Caption 2 of 160 Photos: Hong Kong unrest Pro-democracy supporters wave flags during a countdown party in Tsim Sha Tsui district on New Year's Eve. Hide Caption 3 of 160 Photos: Hong Kong unrest Police arrive to conduct a clearance operation in the Kowloon district of Hong Kong on December 31. Hide Caption 4 of 160 Photos: Hong Kong unrest Protesters take photos of a 'Free HK' light display at a gathering in the Central district of Hong Kong on December 30. Hide Caption 5 of 160 Photos: Hong Kong unrest A man is detained by riot police during a demonstration in a shopping mall at Sheung Shui district on December 28. Hide Caption 6 of 160 Photos: Hong Kong unrest A protester reacts after police fire tear gas to disperse bystanders in the Jordan district of Hong Kong, early on December 25. Hide Caption 7 of 160 Photos: Hong Kong unrest People celebrating the holidays react to tear gas as police confront protesters on Christmas Eve. Hide Caption 8 of 160 Photos: Hong Kong unrest Protesters march in Hong Kong. Hide Caption 9 of 160 Photos: Hong Kong unrest Protesters stage a rally outside the US Consulate in Hong Kong on Sunday, December 1. Hundreds gathered Sunday afternoon outside the US Consulate for another pro-US rally to show support for President Trump after he signed the Hong Kong Human Rights and Democracy Act into law. Hide Caption 10 of 160 Photos: Hong Kong unrest People take part in a march from Tsim Sha Tsui to Hung Hom in Hong Kong on December 1. Hide Caption 11 of 160 Photos: Hong Kong unrest Pro-democracy candidate Jimmy Sham, right, celebrates with a supporter after winning his election in the Sha Tin district, early November 25. "Today's result represents (my constituency's) support to protesters. The government should immediately establish the Five Demands and respond to the public's voices," Sham posted on Facebook, referencing a long-standing protest slogan. Hide Caption 12 of 160 Photos: Hong Kong unrest Pro-democracy candidate James Yu hugs his girlfriend after winning his seat in district council elections, early November 25. Hide Caption 13 of 160 Photos: Hong Kong unrest People line up to vote outside of a polling place in Hong Kong, November 24. More than 2.9 million people turned out to vote in Sunday's elections, which have been framed as a de facto referendum on the almost six months of ongoing protests. Hide Caption 14 of 160 Photos: Hong Kong unrest Hong Kong Chief Executive Carrie Lam casts her ballot for the district council elections at a polling place, November 24. In a statement Monday, Lam said her government "respects the election results." Hide Caption 15 of 160 Photos: Hong Kong unrest A group of protesters leave the Hong Kong Polytechnic University holding hands before surrendering to police in the Hung Hom district on November 22. Hide Caption 16 of 160 Photos: Hong Kong unrest Protesters use clothes and helmets to form "SOS" at Hong Kong Polytechnic University on November 21. Hide Caption 17 of 160 Photos: Hong Kong unrest Protesters raise their hands to represent the five demands of pro-democracy demonstrators during a rally in support of the Hong Kong Human Rights and Democracy Act in the U.S., at the IFC Mall in Hong Kong, on November 21. Hide Caption 18 of 160 Photos: Hong Kong unrest Tables and chairs piled up to create a barrier are left behind by protesters who barricaded themselves inside the Hong Kong Polytechnic University. Hide Caption 19 of 160 Photos: Hong Kong unrest A Fire Services Department rescue diver prepares to enter the sewage system on November 20 to search for protesters who escaped from the Hong Kong Polytechnic University. Hide Caption 20 of 160 Photos: Hong Kong unrest Police detain a group of people after they tried to flee the Hong Kong Polytechnic University campus on November 19. Last week, thousands of student protesters streamed into the university and occupied the campus as the city's violent political unrest reached fever pitch. Hide Caption 21 of 160 Photos: Hong Kong unrest A protester uses a flashlight while crawling through a sewer tunnel to see how wide it is as he and others try to find an escape route from the Hong Kong Polytechnic University on November 19. Hide Caption 22 of 160 Photos: Hong Kong unrest A protester walks through a gymnasium at Hong Kong Polytechnic University on November 19. Hide Caption 23 of 160 Photos: Hong Kong unrest Protesters react as police fire tear gas in the Kowloon area of Hong Kong, Monday, November 18. Hide Caption 24 of 160 Photos: Hong Kong unrest Firefighters put out a burning car set on fire by protesters near Hong Kong Polytechnic University in the Tsim Sha Tsui district on November 18. Hide Caption 25 of 160 Photos: Hong Kong unrest Police in riot gear move through a cloud of smoke as they detain a protester at the Hong Kong Polytechnic University in Hong Kong on November 18. Police have attempted to clear the university , which has been occupied by protesters for days as a strategic protest base. Hide Caption 26 of 160 Photos: Hong Kong unrest Police fire tear gas as protesters attempt to leave Hong Kong Polytechnic University via a bridge on November 18. Hide Caption 27 of 160 Photos: Hong Kong unrest A member of the police clashes with a protester at the Hong Kong Poytechnic University on November 18. Hide Caption 28 of 160 Photos: Hong Kong unrest Protesters use a rope to lower themselves from a pedestrian bridge to waiting motorbikes to escape from police at Hong Kong Polytechnic University on November 18. Hide Caption 29 of 160 Photos: Hong Kong unrest A protester throws an umbrella onto a fire at the barricaded main entrance of Hong Kong Polytechnic University on November 18. Hide Caption 30 of 160 Photos: Hong Kong unrest An anti-government protester is detained at Hong Kong Polytechnic University on November 18. Hide Caption 31 of 160 Photos: Hong Kong unrest An anti-government protester is showered down by volunteer medical workers after he was soaked by a police water cannons firing pepper spray-infused water at Hong Kong Polytechnic University on November 18. Hide Caption 32 of 160 Photos: Hong Kong unrest Riot police fire tear gas and rubber bullets as protesters attempt to leave Hong Kong Poytechnic University on November 18. Hide Caption 33 of 160 Photos: Hong Kong unrest A protester prepares to shoot an arrow during a confrontation with police. Hide Caption 34 of 160 Photos: Hong Kong unrest Police use a water cannon outside the Hong Kong Polytechnic University. Hide Caption 35 of 160 Photos: Hong Kong unrest A protester throws a Molotov cocktail at police on November 17. Hide Caption 36 of 160 Photos: Hong Kong unrest Protesters use a catapult to fire bricks at the police from inside the Hong Kong Polytechnic University on November 17. Hide Caption 37 of 160 Photos: Hong Kong unrest A woman tries to hold back riot police from approaching the Hong Kong University in Hong Kong on Saturday. Hide Caption 38 of 160 Photos: Hong Kong unrest Protesters train to throw Molotov cocktails into a swimming pool on the campus of the Hong Kong Polytechnic University on November 14. Hide Caption 39 of 160 Photos: Hong Kong unrest Protesters walk past barricades of bricks on a road near the Hong Kong Polytechnic University on November 14. Hide Caption 40 of 160 Photos: Hong Kong unrest Demonstrators gather during a lunchtime protest in the financial district of Hong Kong on November 14. Hide Caption 41 of 160 Photos: Hong Kong unrest A protester releases a flaming arrow to light a barricade at The Chinese University of Hong Kong (CUHK), Wednesday, November 13. Hide Caption 42 of 160 Photos: Hong Kong unrest A Molotov cocktail, a gas mask and a yellow construction helmet are placed upon a bust of late hotel tycoon Hui Yeung Shing at the campus of The Chinese University of Hong Kong on November 13. Hide Caption 43 of 160 Photos: Hong Kong unrest A fire is seen at a Mass Transit Railway (MTR) station during a demonstration at The Chinese University of Hong Kong on November 13. Hide Caption 44 of 160 Photos: Hong Kong unrest Students attempt to clear tear gas canisters fired by riot police onto a sports track during a confrontation at the Chinese University in Hong Kong on Tuesday, November 12. Hide Caption 45 of 160 Photos: Hong Kong unrest A man is detained during a protest at the Chinese University of Hong Kong on November 12. Hide Caption 46 of 160 Photos: Hong Kong unrest Students block an escalator with chairs in an attempt to hamper police at the University of Hong Kong on November 12. Hide Caption 47 of 160 Photos: Hong Kong unrest A protester is detained in the Central District of Hong Kong on November 11. Hide Caption 48 of 160 Photos: Hong Kong unrest People react after tear gas was fired by police during a protest in Hong Kong's Central District on November 11. Hide Caption 49 of 160 Photos: Hong Kong unrest Riot police face off with protesters at an entrance of a shopping mall during a demonstration on November 10. Hide Caption 50 of 160 Photos: Hong Kong unrest A man is helped by a volunteer medic after police used pepper spray during a demonstration on November 10. Hide Caption 51 of 160 Photos: Hong Kong unrest Students of the Hong Kong University of Science and Technology (HKUST) participate in a march on November 8, after hospital officials confirmed the death of student Chow Tsz-lok , 22. Police say Chow, a computer sciences student at HKUST, fell from the third floor to the second floor of a parking garage in the residential area of Tseung Kwan O in the early hours of November 4. Hide Caption 52 of 160 Photos: Hong Kong unrest A person places a flower at a memorial for 22-year-old Hong Kong university student Chow Tsz-lok on November 8. Hide Caption 53 of 160 Photos: Hong Kong unrest Students in gas masks are seen during a graduation ceremony at the Chinese University of Hong Kong on Thursday, November 7 in Hong Kong. Hide Caption 54 of 160 Photos: Hong Kong unrest Firefighters stand outside the offices of China's Xinhua News Agency after its windows were damaged by protesters in Hong Kong on Saturday, November 2. Hong Kong riot police fired multiple rounds of tear gas and used a water cannon Saturday to break up a rally by thousands of masked protesters demanding autonomy after Beijing indicated it could tighten its grip on the Chinese territory. Hide Caption 55 of 160 Photos: Hong Kong unrest Richard Chan, a candidate for the district council elections, reacts after being pepper-sprayed by police in Hong Kong on November 2. Hide Caption 56 of 160 Photos: Hong Kong unrest Thousands of black-clad masked protesters streamed into Hong Kong's central shopping district for another rally on November 2. Hide Caption 57 of 160 Photos: Hong Kong unrest A person dressed as President Donald Trump waves an American flag on a street in Hong Kong on Thursday, October 31, 2019. Hong Kong authorities braced as pro-democracy protesters urged people on Thursday to celebrate Halloween by wearing masks on a march in defiance of a government ban on face coverings Hide Caption 58 of 160 Photos: Hong Kong unrest A man dressed as the Joker for Halloween walks past police officers on October 31. Hide Caption 59 of 160 Photos: Hong Kong unrest Pro-democracy activist Joshua Wong (second from left) and Kelvin Lam (second from right) shout slogans as they meet the media outside the Legislative Council (LegCo) in Hong Kong on October 29, 2019, after Wong was barred from standing in an upcoming local election. Hide Caption 60 of 160 Photos: Hong Kong unrest A protester throws a tear gas canister on October 27 in Hong Kong. Hide Caption 61 of 160 Photos: Hong Kong unrest A couple wearing Guy Fawkes masks watch a rally at Chater Garden in Hong Kong on October 26. Hide Caption 62 of 160 Photos: Hong Kong unrest Protesters start a fire in front of the MTR station during demonstration on October 27. Hide Caption 63 of 160 Photos: Hong Kong unrest Tear gas smoke is seen exploding over reporters during an anti-government protest in Mong Kok district in Hong Kong on October 27. Hide Caption 64 of 160 Photos: Hong Kong unrest High school students take part in a human chain rally outside Kowloon park in Hong Kong on October 25. Hide Caption 65 of 160 Photos: Hong Kong unrest Police fire blue dye toward protesters in Hong Kong on Sunday, October 20. Blue dye can be used to stain and identify masked protesters. Hide Caption 66 of 160 Photos: Hong Kong unrest A pro-democracy protester is arrested by police on October 20. Hide Caption 67 of 160 Photos: Hong Kong unrest Pro-democracy lawmakers protest as Hong Kong Chief Executive Carrie Lam delivers a speech at the Legislative Council on Wednesday, October 16. Lam's annual policy address ended in chaos as pro-democracy lawmakers repeatedly disrupted her speech and heckled her with calls to honor the demands of anti-government protesters. Hide Caption 68 of 160 Photos: Hong Kong unrest A protester shoots a basketball at a poster of Lam during a rally on Tuesday, October 15. Hide Caption 69 of 160 Photos: Hong Kong unrest Protesters set fire to a Bank of China branch on Sunday, October 13. It was the 19th consecutive weekend of anti-government protests in Hong Kong. Hide Caption 70 of 160 Photos: Hong Kong unrest Protesters use the lights on their phones during a rally in central Hong Kong's business district. Hide Caption 71 of 160 Photos: Hong Kong unrest A protester attempts to break a tourist bus window on October 13. Hide Caption 72 of 160 Photos: Hong Kong unrest Protesters wearing masks in defiance of a recently imposed ban gather at a shopping mall on October 13. Hide Caption 73 of 160 Photos: Hong Kong unrest Supporters surround a police bus carrying political activist Edward Leung as it leaves the High Court in Hong Kong on Wednesday, October 9. Several hundred masked protesters gathered at Hong Kong's High Court for the appeal hearing of Leung, who was sentenced to six years in prison for his part in a violent clash with police. Hide Caption 74 of 160 Photos: Hong Kong unrest A woman is treated after police fired tear gas to disperse protesters in the Mong Kok district of Hong Kong on October 7. Hide Caption 75 of 160 Photos: Hong Kong unrest Pro-democracy protesters gather in a shopping mall on October 7. Hide Caption 76 of 160 Photos: Hong Kong unrest Rescue personnel check the bottom of a taxi after the driver allegedly drove onto the pavement, hitting protesters in Hong Kong on October 6. Hide Caption 77 of 160 Photos: Hong Kong unrest A China Construction Bank is seen vandalized in the Causeway Bay area of Hong Kong on October 6. Hide Caption 78 of 160 Photos: Hong Kong unrest Pro-democracy protesters set fires in the street in the Causeway Bay area. Hide Caption 79 of 160 Photos: Hong Kong unrest People protest the ban against masks on Saturday, October 5. Hide Caption 80 of 160 Photos: Hong Kong unrest An anti-government protester stands near a fire on Friday, October 4. Hide Caption 81 of 160 Photos: Hong Kong unrest Protesters move a statue depicting a protester armed with gas mask, helmet and umbrella on the streets of Hong Kong on October 4. Hide Caption 82 of 160 Photos: Hong Kong unrest Protesters set a fire at a China Construction Bank. Hide Caption 83 of 160 Photos: Hong Kong unrest Protesters spray paint slogans at the entrance to a tunnel on October 4. Hide Caption 84 of 160 Photos: Hong Kong unrest A store is in shambles after being vandalized by protesters. Hide Caption 85 of 160 Photos: Hong Kong unrest Pro-democracy demonstrators hold up their hands to symbolize their five demands during a rally on October 4. Hide Caption 86 of 160 Photos: Hong Kong unrest Protesters throw petrol bombs at the gate to the Tsuen Wan police station on Wednesday, October 2. Hide Caption 87 of 160 Photos: Hong Kong unrest Schoolmates of a student who was shot in the chest by police place their hands on their chests during a protest on October 2. Hide Caption 88 of 160 Photos: Hong Kong unrest A young protester was shot Tuesday, October 1, as violent protests erupted across Hong Kong on the 70th anniversary of the People's Republic of China. The incident marked a major escalation in violence that could galvanize the protest movement in Hong Kong. Hide Caption 89 of 160 Photos: Hong Kong unrest Police detain an anti-government protester on October 1. Thousands of black-clad protesters marched in central Hong Kong as part of multiple pro-democracy rallies. Hide Caption 90 of 160 Photos: Hong Kong unrest Police tackle and arrest pro-democracy protesters during clashes on October 1. Hide Caption 91 of 160 Photos: Hong Kong unrest A protester is seen carrying rocks on a street on October 1. While events in Beijing were being held to mark the 70th anniversary of the founding of the People's Republic of China, demonstrators rallied throughout Hong Kong. Hide Caption 92 of 160 Photos: Hong Kong unrest Protesters react after police fired tear gas near the central government offices in Hong Kong's Admiralty area on October 1. Hide Caption 93 of 160 Photos: Hong Kong unrest Pro-democracy protesters form a "Pepe the Frog" themed human chain on Monday, September 30. Hide Caption 94 of 160 Photos: Hong Kong unrest A man is detained by Hong Kong police during a protest in the Causeway Bay shopping district on Sunday, September 29. Hide Caption 95 of 160 Photos: Hong Kong unrest Bus passengers look at a burning barricade lit by pro-democracy protesters in front of the Mong Kok police station on Sunday, September 22. Hide Caption 96 of 160 Photos: Hong Kong unrest Pro-democracy protesters sing songs and chant slogans during a rally inside a shopping mall on September 22. Hide Caption 97 of 160 Photos: Hong Kong unrest A pro-China supporter, center, is escorted by police after confronting journalists in Hong Kong on September 15. Hide Caption 98 of 160 Photos: Hong Kong unrest Pro-government and anti-government supporters chant against one another at a shopping mall in Hong Kong on Friday, September 13. The sign translates to "Stop violence and curb chaos; safeguard Hong Kong." Hide Caption 99 of 160 Photos: Hong Kong unrest Demonstrators hold up their cell phone lights as they form a human chain at the Peak, a tourist spot in Hong Kong, on September 13. Hide Caption 100 of 160 Photos: Hong Kong unrest Police escort an injured man after he attacked protesters outside Prince Edward station in Hong Kong on Friday, September 6. Hide Caption 101 of 160 Photos: Hong Kong unrest Protesters burn paper money to pay their respects to injured protesters. Hide Caption 102 of 160 Photos: Hong Kong unrest Protesters prepare to clash with police outside the Mong Kok police station on September 6. Hide Caption 103 of 160 Photos: Hong Kong unrest A protester is detained by police at the Po Lam Mass Transit Railway station on Thursday, September 5. Hide Caption 104 of 160 Photos: Hong Kong unrest A man watches televisions at a store in Hong Kong as Chief Executive Carrie Lam announces the withdrawal of the extradition bill on Wednesday, September 4. Hide Caption 105 of 160 Photos: Hong Kong unrest A woman gets emotional on September 4 while paying her respects to protesters who were injured a few days earlier. Hide Caption 106 of 160 Photos: Hong Kong unrest Demonstrators travel through a railway station during a rally on Tuesday, September 3. Hide Caption 107 of 160 Photos: Hong Kong unrest Students wearing gas masks and helmets hold a banner that reads "five major demands are indispensable" at St. Francis' Canossian College in Hong Kong. Hide Caption 108 of 160 Photos: Hong Kong unrest Protesters gather in the bus terminal at Hong Kong International Airport on Sunday, September 1. Hundreds of pro-democracy activists attempted to block transport routes to the city's airport. Hide Caption 109 of 160 Photos: Hong Kong unrest A passenger walks to the airport on September 1 as pro-democracy protesters blocked a road outside the airport. Hide Caption 110 of 160 Photos: Hong Kong unrest A protester uses a slingshot outside the Central Government Complex during clashes with police on Saturday, August 31. Thousands of pro-democracy protesters held an anti-government rally one day after several leading activists and lawmakers were arrested in a sweeping crackdown. Hide Caption 111 of 160 Photos: Hong Kong unrest Protesters light a Molotov cocktail on August 31. Hide Caption 112 of 160 Photos: Hong Kong unrest Protesters take cover as policemen fire blue-colored water on them. Blue dye can be used to stain and identify masked protesters. Hide Caption 113 of 160 Photos: Hong Kong unrest A surveillance camera is covered with white paint during protests. Hide Caption 114 of 160 Photos: Hong Kong unrest An overhead view shows protesters reacting after police fired tear gas on August 31. Hide Caption 115 of 160 Photos: Hong Kong unrest Pro-democracy activists Agnes Chow and Joshua Wong speak to the media after they were released on bail at the Eastern Magistrates Courts on Friday, August 30. They were arrested earlier the same day in a dragnet across Hong Kong. Hide Caption 116 of 160 Photos: Hong Kong unrest Protesters clash with police after a rally in Hong Kong's Tsuen Wan district on Sunday, August 25. It was one of the most violent nights seen in Hong Kong since mass protests began in June. Hide Caption 117 of 160 Photos: Hong Kong unrest A police officer aims a gun in front of a protester on August 25. Hide Caption 118 of 160 Photos: Hong Kong unrest Some protesters shine laser pointers at police lines on August 25. Hide Caption 119 of 160 Photos: Hong Kong unrest Protesters pick up bricks to be used as projectiles on August 24.

Hide Caption 120 of 160 Photos: Hong Kong unrest Police retreat after clashing with protesters on August 24. Hide Caption 121 of 160 Photos: Hong Kong unrest Cell phones shine from the top of Lion Rock on August 23. Hide Caption 122 of 160 Photos: Hong Kong unrest Protesters march under umbrellas on Sunday, August 18. Hide Caption 123 of 160 Photos: Hong Kong unrest Tens of thousands of protesters showed up in the streets on August 18. Hide Caption 124 of 160 Photos: Hong Kong unrest A protester participates in a march on Saturday, August 17. His eye is covered with red gauze, referencing a woman who was allegedly shot in the eye with a beanbag round during clashes between protesters and police. Hide Caption 125 of 160 Photos: Hong Kong unrest Protesters point lasers at the Sham Shui Po police station on August 14. Hide Caption 126 of 160 Photos: Hong Kong unrest A police officer falls over an airport luggage trolley during a scuffle with pro-democracy protesters on Tuesday, August 13. For two days, protesters flooded the airport. Check-ins were suspended and dozens of outgoing flights were canceled. Hide Caption 127 of 160 Photos: Hong Kong unrest A traveler passes her luggage to security guards as she tries to enter the departures gate. Hide Caption 128 of 160 Photos: Hong Kong unrest A display board shows canceled flights on August 13. Hide Caption 129 of 160 Photos: Hong Kong unrest Medics look after a woman who received a facial injury during clashes on Sunday, August 11. Hide Caption 130 of 160 Photos: Hong Kong unrest A pro-democracy protester is held by police outside the Tsim Sha Tsui police station on August 11. Hide Caption 131 of 160 Photos: Hong Kong unrest Police fire tear gas at protesters during a demonstration in the Wong Tai Sin District on Monday, August 5. Hide Caption 132 of 160 Photos: Hong Kong unrest A train passenger gestures toward a protester, right, who was preventing the doors of a train from closing on August 5. The protester was trying to disrupt Hong Kong's morning rush-hour commute. Hide Caption 133 of 160 Photos: Hong Kong unrest A man comforts his pregnant wife near a train platform after protesters blocked the train doors on August 5. Hide Caption 134 of 160 Photos: Hong Kong unrest A protester stands in tear gas during a confrontation with police in the early hours of Sunday, August 4. Hide Caption 135 of 160 Photos: Hong Kong unrest A Chinese flag floats in water after it was thrown by protesters during a demonstration on Saturday, August 3. Hide Caption 136 of 160 Photos: Hong Kong unrest Members of Hong Kong's medical sector attend a protest in Edinburgh Place on Friday, August 2. Hide Caption 137 of 160 Photos: Hong Kong unrest The emblem on the China Liaison Office is protected by plexiglass during a demonstration on Sunday, July 28. Hide Caption 138 of 160 Photos: Hong Kong unrest A protester flees from baton-wielding police in the Yuen Long district of Hong Kong on Saturday, July 27. Hide Caption 139 of 160 Photos: Hong Kong unrest A protester looks through umbrellas during the clashes with police on July 27. Hide Caption 140 of 160 Photos: Hong Kong unrest Travelers watch as protesters rally at Hong Kong's international airport on Friday, July 26. Hide Caption 141 of 160 Photos: Hong Kong unrest Protesters clash with police on Sunday, July 21. Hide Caption 142 of 160 Photos: Hong Kong unrest Masked men in white T-shirts are seen after attacking anti-extradition bill demonstrators at a train station in Yuen Long. Hide Caption 143 of 160 Photos: Hong Kong unrest Medical workers help a protester affected by tear gas on July 21. Hide Caption 144 of 160 Photos: Hong Kong unrest The office of pro-Beijing lawmaker Junius Ho was trashed by protesters in Hong Kong's Tsuen Wan district. Hide Caption 145 of 160 Photos: Hong Kong unrest Police officers use pepper spray to disperse protesters after a rally in the Sheung Shui district on Saturday, July 13. Hide Caption 146 of 160 Photos: Hong Kong unrest A demonstrator sprays paint inside a chamber at Hong Kong's Legislative Council building, where protesters forced their way in on Monday, July 1. Hide Caption 147 of 160 Photos: Hong Kong unrest A protester smashes a window of the Legislative Council building. Hide Caption 148 of 160 Photos: Hong Kong unrest Columns of sunlight are cast on a crowd during the march on July 1. Hide Caption 149 of 160 Photos: Hong Kong unrest Helicopters carrying the flags of China and Hong Kong fly over demonstrators on July 1. Hide Caption 150 of 160 Photos: Hong Kong unrest A police officer uses pepper spray during a clash with protesters on July 1. Hide Caption 151 of 160 Photos: Hong Kong unrest A protester wearing a T-shirt with the word "revolution" walks past an inscription on a road that reads "Long Live HK." Hide Caption 152 of 160 Photos: Hong Kong unrest Police detain protesters near the government headquarters in Hong Kong on July 1. Hide Caption 153 of 160 Photos: Hong Kong unrest An overhead view shows thousands of protesters marching through a Hong Kong street on Sunday, June 16. Hide Caption 154 of 160 Photos: Hong Kong unrest Protesters run after police fired tear gas on Wednesday, June 12. Hide Caption 155 of 160 Photos: Hong Kong unrest By the morning of June 12, tens of thousands of mainly young people had arrived in the area, blocking streets and bringing central Hong Kong to a standstill. Hide Caption 156 of 160 Photos: Hong Kong unrest A demonstrator holds a sign during the June 12 rally. Hide Caption 157 of 160 Photos: Hong Kong unrest Police officers charge toward protesters during clashes on Monday, June 10. It was a continuation of protests that started the day before. Hide Caption 158 of 160 Photos: Hong Kong unrest Protesters on June 9 waved placards and wore white -- the designated color of the rally. "Hong Kong, never give up!" some chanted. Hide Caption 159 of 160 Photos: Hong Kong unrest Students wear chains during a demonstration on Saturday, June 8. Hide Caption 160 of 160

Here again, police tactics were noticeably harsher than in earlier days of protests. They repeatedly use water cannon, only the second occasion this summer, and deployed hundreds of officers to the streets, charging protester lines and carrying out dozens of arrests.

The water cannon fired blue dye, which typically leaves a residual stain making it easier to identify participants for arrest later.

Ordered in 2015, police had resisted using water cannon for nearly three months. Now that tool has been deployed from their arsenal, it has quickly become normalized. Protesters are adapting just as quickly, sharing information online on how to get rid of the blue stains.

As both police and protesters continue to escalate their tactics with no sign of the unrest halting, fears grow that the government will turn to the Chinese military for support in putting the protests down.

Last week, thousands of new troops from the Chinese People's Liberation Army (PLA) joined the garrison in the city . The PLA described it as a usual annual rotation of staff, but US military officials told CNN they had seen no evidence that existing forces left the garrison, and suggested it instead may have been significantly reinforced.

All eyes will be on Lam this week to see if she institutes such powers -- or if she asks the PLA garrison for assistance in controlling the protests.

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HK officials stalling, or powerless to act

As the smoke and tear gas clears after the weekend's violence, escalation on both sides appears to be the only thing on the cards.

While Lam has made gestures towards meeting with young people, and potentially with protester representatives, she has also repeatedly refused to negotiate when it comes to the opposition movement's five core demands. These include a complete withdrawal of the currently suspended extradition bill that kicked off this whole mess, an independent investigation into allegations of police brutality, and the restarting of long-stalled political reform.

Saturday's protests marked five years since Beijing ruled out true universal suffrage for how the city's chief executive is chosen. In the type of tin-eared statement that has characterized the Hong Kong government's response to the crisis, a city spokesman said Saturday -- to the rage of many already on the streets -- that "rashly embarking on political reform again will further polarize society, which is an irresponsible act."

The government is offering protesters few choices. They can go home and pin their hopes on a vague promise of future negotiations once the violence has stopped, or continue protesting until the government cracks down.

Hong Kong officials may not be the ones choosing this strategy -- Reuters reported last week that Lam suggested a compromise in August but was overruled by Beijing -- but they do not have the cards to risk such a bluff. Lam had apparently mooted a withdrawal of the extradition bill in order to defuse the crisis, but Beijing ordered a hard line.

CNN has reached out to the Hong Kong-Macao Affairs Office and the Office of Chief Executive Carrie Lam for comment on the Reuters report. China's foreign ministry on Friday reiterated that the central government "supports, respects and understands" the Hong Kong government's position on protester demands.

In a strident commentary Sunday, Chinese state news agency Xinhua said that "violence in Hong Kong must end now."

The Hong Kong government and police "took decisive measures to enforce the law and stop the violence, sending a clear warning to the rioters," Xinhua said. "The end is coming for those attempting to disrupt Hong Kong and antagonize China."

A woman holds a cross in front of the Mongkok Police Station as riot police holding shields stand guard during a standoff with protesters after an anti-government rally in on September 1, 2019, in Hong Kong.

What a crackdown might look like

The PLA has had a presence in Hong Kong since the 1997 handover from British control, but has remained very much in the background in a city where a large memorial for the Tiananmen Square massacre is held each year.

The sight of PLA troops patrolling Hong Kong's streets, let alone using force, has long been feared as a symbolic point of no return for the city.

The Tiananmen parallels would be hard to avoid even in a peaceful operation, and analysts agree that it would risk crashing the city's economy , sending foreign firms and investors scrambling for the exits. Censorship of local media or the internet could have a similar effect

Who would be the most hurt by this? Probably not the young people who make up the most radical, violent core of the protests. For many of them, a future under full Chinese rule -- approaching fast in 2047 under current constitutional arrangements -- is a hopeless prospect.

Already at the sharp end of Hong Kong's horrendous economic inequality and unfair housing system, they are also less concerned about inflicting economic damage. Nothing has hurt the city's global standing more than protests at the airport, but radical groups have continued to target it, seeing it as a weak point to exploit and one that draws significant international attention.

Protesters gather on a road as police fire tear gas outside the government headquarters in Hong Kong on August 31, 2019.

Hardcore protesters sometimes appear to relish the thought of PLA troops on the streets, seeing it as proof of their ability to shake the foundation of not only the Hong Kong government but also the powers in Beijing.

"Good! We are ready for it, we want it!" protesters told CNN during ugly scenes of mob violence at the city's airport last month, when asked about what could happen in the event of a PLA crackdown.

"Give me liberty or give me death," read graffiti left by protesters after more chaotic scenes near the airport on Sunday.

Graffiti on a wall in Tung Chung, where protesters fled after disrupting transport to and from Hong Kong airport.

Whether Lam can handle the repercussions of a decision to clamp down militarily is much less clear. Any local support she has comes from the city's elite, the tycoons who profited off the city's yawning inequality and huge influx of Chinese capital, and have kept their noses out of the city's current political crisis.

Should PLA troops be deployed to help secure the city -- or, worse, a full-scale military crackdown ordered -- she would be immortalized as the figurehead of that decision: the chief executive who oversaw the worst crisis in Hong Kong's history -- and did not act to stop it.

damage by maintaining its uncompromising stance. The Chinese economy is Beijing may already be risking economic and societaldamage by maintaining its uncompromising stance. The Chinese economy is facing a multitude of challenges -- weak growth, high levels of debt, and, of course, the ongoing trade war with the US. Economic collapse, or even the slowdown of Hong Kong, could have knock-on effects north of the border, ones that could quickly spin out of Beijing's control.

In a statement Sunday calling for a general strike, the Hong Kong Confederation of Trade Unions blamed the ongoing crisis squarely on the government. "We must save Hong Kong from institutional collapse," the group warned. "Hong Kong is our beloved home; our jobs, livelihoods, family, and friends that we cherish are all here. We cannot let those who are in power continue to ravage the home that we always hold dear."

If the increasingly violent protesters are the ones who have turned Hong Kong into a tinderbox, it's the government holding the matches. One wrong move now could see the whole city burn.