Protesters have taken to the streets of Hong Kong for another round of mass anti-government demonstrations as political unrest continues to roil the city.

Ahead of a city-wide strike and simultaneous protests in seven districts, on Sunday night protesters evaded and frustrated the police by holding flashmob demonstrations. Groups of protesters scattered, switching locations at the last minute and disappearing before riot police were able to arrive en masse.

Protesters deviated from a previously planned rally in Hong Kong’s Western district, where police had prepared to defend China’s liaison office, a target in previous unrest.

Demonstrators moved east to Causeway Bay, a major shopping district where they occupied main roads and disrupted traffic. Police fired several rounds of teargas on protesters there but many had already moved to other locations.

In a park in Wan Chai, protesters defaced a statue of a golden bauhinia flower, a gift from China when Hong Kong was returned to Chinese control in 1997. The monument was spraypainted with the words: “Heaven will destroy the Communist party,” and “Liberate Hong Kong”.

Protesters light a fire during a rally in Causeway Bay. Photograph: Chan Long Hei/EPA

This is the ninth week of consecutive protests in Hong Kong, as the semi-autonomous city faces a political crisis that has deepened as authorities have tried to suppress it. Hong Kong’s chief executive, Carrie Lam, has disappeared from public view over the last two weeks.

“I came to support Hong Kong. We are showing our guts to the government,” said Peter Tsang, 32, who attended the march in Tseung Kwan O. “A lot of people have come and they are stepping up because Carrie Lam has not come out of hiding.”

In a statement released in the early hours of Monday, the Hong Kong government said “the deteriorating situation” showed protests were “spreading [and] pushing Hong Kong to the verge of a very dangerous situation.”

Quick Guide What are the Hong Kong protests about? Show Why are people protesting? The protests were triggered by a controversial bill that would have allowed extraditions to mainland China, where the Communist party controls the courts, but have since evolved into a broader pro-democracy movement. Public anger – fuelled by the aggressive tactics used by the police against demonstrators – has collided with years of frustration over worsening inequality and the cost of living in one of the world's most expensive, densely populated cities. The protest movement was given fresh impetus on 21 July when gangs of men attacked protesters and commuters at a mass transit station – while authorities seemingly did little to intervene. Underlying the movement is a push for full democracy in the city, whose leader is chosen by a committee dominated by a pro-Beijing establishment rather than by direct elections.

Protesters have vowed to keep their movement going until their core demands are met, such as the resignation of the city’s leader, Carrie Lam, an independent inquiry into police tactics, an amnesty for those arrested and a permanent withdrawal of the bill. Lam announced on 4 September that she was withdrawing the bill. Why were people so angry about the extradition bill? Beijing’s influence over Hong Kong has grown in recent years, as activists have been jailed and pro-democracy lawmakers disqualified from running or holding office. Independent booksellers have disappeared from the city, before reappearing in mainland China facing charges. Under the terms of the agreement by which the former British colony was returned to Chinese control in 1997, the semi-autonomous region was meant to maintain a “high degree of autonomy” through an independent judiciary, a free press and an open market economy, a framework known as “one country, two systems”. The extradition bill was seen as an attempt to undermine this and to give Beijing the ability to try pro-democracy activists under the judicial system of the mainland. How have the authorities responded? Beijing has issued increasingly shrill condemnations but has left it to the city's semi-autonomous government to deal with the situation. Meanwhile police have violently clashed directly with protesters, repeatedly firing teargas and rubber bullets. Beijing has ramped up its accusations that foreign countries are “fanning the fire” of unrest in the city. China’s top diplomat Yang Jiechi has ordered the US to “immediately stop interfering in Hong Kong affairs in any form”. Lily Kuo and Verna Yu in Hong Kong

As the protests wear on, demonstrators have begun shifting strategies while authorities arrest more people and deploy harsher tactics against them. Police have arrested more than 60 people and charged 44 of them with rioting, a crime that could mean up to 10 years in prison.

“The protesters are trying to use up the energy of the police,” said Yan, 26, a protester in Causeway Bay. “We don’t want anyone to be arrested or hurt any more, so we didn’t stay in set places. We can be more flexible.”

On Sunday, people blocked Hong Kong’s cross-harbour tunnel and another group of protesters surrounded a police station in the outer district of Kwun Tong, , where they shined lasers at the police and threw bricks at the compound. Earlier in the day, after a peaceful rally in Tseung Kwan O in Hong Kong’s New Territories, protesters broke the windows of a police station, using a makeshift catapult to launch objects at the building.

A homemade slingshot is used to fire bricks at the Tseung Kwan O police station. Photograph: Vincent Thian/AP

The protests, which began over an extradition bill to send suspects to China, have turned into a broader political movement demanding accountability from the Hong Kong government, which ultimately answers to Beijing.

The former British colony, which reverted to Chinese control in 1997, is meant to enjoy a “high degree” of autonomy from the mainland as part of the “one country, two systems” framework, but residents say their freedoms are slowly disappearing under China’s influence.

The police have been criticised for what some say have been overly harsh tactics towards protesters, many of them students or recent graduates. In July, dozens of masked men dressed in white beat commuters with iron and wooden rods, shocking Hongkongers and eroding trust in the police, who did not stop the attack.

Anger at the police and the Hong Kong government has spread from the protesters to the general public, as thousands of residents have joined weekend rallies and protests. Sunday’s protests marked the fourth day in a row of mass demonstrations.

On Saturday, protesters clashed with police in several locations in Kowloon, as police fired teargas and pepper spray on crowds occupying main roads and areas outside police stations, following a peaceful march earlier in the day. Thousands of civil servants and medical staff rallied on Friday, while those from Hong Kong’s finance sector held a flashmob protest on Thursday.

On Sunday, residents were handing out vouchers, food and supplies to protesters. On Saturday night and the early hours of Sunday, residents in a working-class district surrounded police, demanding the release of arrested protesters.

“At the beginning, we were alone. No one understood us,” said one demonstrator who asked not to give his name, adding that more people have been donating protective gear and supplies to the protests. “More people are coming out, which is better and there is more support.”

Anti-extradition bill protesters stand behind makeshift shields in Lam Tin station. Photograph: Jérôme Favre/EPA

Protesters say police also appear to be changing their strategies, mostly keeping their distance and using teargas to disperse protesters instead of clashing directly with them. Others say the police appear to be waiting out the protesters, prolonging the standoffs and disruptions on the streets, perhaps in the hope of frustrating the general public.

“They wait until we are exhausted and the protests become stretched out. They are trying to change public perception,” said one protester, 29-year-old William.

Protesters believe that strategy will not work as smaller, dispersed protests like Sunday’s continue. “A little spark can catch fire, and it is spreading quickly,” added William.

“It’s a long-term protest. Some people might think we are acting like rioters, but looking back at history there is no peaceful revolution,” said Yan.

Some protesters stayed home, preparing for Monday’s mass strikes. Simultaneous rallies will take place in seven of Hong Kong’s 18 districts. Coffee shops and small businesses posted signs on their doors to say they would be closed on Monday. Workers from the transport sector have also pledged to stay home, potentially paralysing the city’s public transportation network.

As tensions in Hong Kong escalate, observers have been watching for signs of Beijing intervening. Chinese officials have not ruled out the possibility of deploying the People’s Liberation Army, which has a garrison in Hong Kong.

On Sunday, state media published several articles condemning protesters. An editorial in the state news agency Xinhua said: “The central government will not sit idly by and let this situation continue.”