Salvos of tear gas Thursday heralded the start of Hong Kong’s fourth day of continuous, territory-wide unrest and transport disruption as anti-government protesters escalated their efforts to force political concessions from the Beijing-backed government. Students also erected defenses at university campuses, stockpiling homemade weapons.

Early morning volleys of tear gas were fired near the Polytechnic University, where police came under attack from students armed with bows and arrows.

Since Monday, protesters at the university have periodically barricaded the Cross Harbour Tunnel approach roads, which skirt the campus, and last night set fire to tunnel toll booths. The tunnel is the main vehicular artery connecting the Kowloon peninsula to the vital business and banking districts of Hong Kong Island, on the opposite shore of Victoria Harbour.

Students also erected defenses at the Baptist University and at Chinese University, around 25 kilometers from the city center. Chinese University (CUHK)—dubbed “Rioter’s U” by Chinese state media—was on Tuesday the scene of some of the most violent clashes yet in Hong Kong’s five months of unrest.

Local media reported that vehicles had began evacuating staff and students from CUHK in advance of an expected crackdown.

At Hong Kong’s oldest seat of tertiary learning, Hong Kong University (HKU), students were also bracing for police action.

“My parents are very worried about me getting arrested or even killed by police,” said Ezoe, a 20-year-old medical student at HKU. “It is the responsibility of the young generation to work for the future of Hong Kong. It’s up to us to make Hong Kong better.”

She told TIME: “What we are doing is fighting against the Chinese government, not just the Hong Kong government.”

Secondary school students had also turned up to lend a hand.

With all schools suspended for the rest of the week, 13-year-old V. and her friends decided to show their support for the protesters at HKU by bringing them supplies. They used their pocket money and lunch money to buy water and zip ties.

“We won’t eat much today,” said V. who added that none of them told their parents. “I think they know anyways. But what can they do? They won’t stop us.”

In another part of the campus, students were building a brick wall and a large catapult to repel police. “Police were here the day before yesterday,” said Leung, 19, who asked to be identified only by his surname. “We saw they started charging other campuses and so we have to protect ours.”

He joined a group of his classmates attempting to erect the defenses after they saw Chinese University students do the same. “We still don’t really know how to properly mix cement,” he told TIME, as a classmate used a shovel to stir the gravelly mess.

Transport chaos

Commuters meanwhile endured yet another morning of cancelled buses and trains, and gridlocked traffic, as protesters blocked roads and hurled objects onto railway tracks. Many stations have been heavily damaged by protesters, and the station serving CUHK has been virtually destroyed.

One woman, traveling in a car with her husband, told local media that protesters threw a petrol bomb at their vehicle as they attempted to maneuver around an obstruction.

Tensions across the Mass Transit Railway (MTR) network were high as frustrated commuters quarreled and struggled to board the services that remained in operation. Police were called to several stations. Many businesses and shops were shut.

At lunchtime, large crowds of smartly attired office workers joined black-clad protesters in occupying key intersections in the financial district of Central, and also at Quarry Bay in the eastern part of Hong Kong Island. Dressed in collared shirts and slacks or neat skirts, they helped erect roadblocks and ferried supplies to radicals on the barricades.

Many voiced support for CUHK students. In scenes that are now worryingly common, an anti-government mob beat up an elderly man for arguing about the protests. There were also reports of roving gangs attacking young people, amid a call from the leader of a pro-Beijing party for “the general public” to assist the police and “clean up all the roads.”

A first class train carriage is seen after it was vandalised at the University MTR (Mass Transit Railway) train station, that stops at the Chinese University of Hong Kong (CUHK), in Hong Kong on November 14, 2019. ANTHONY WALLACE—AFP via Getty Images

Thursday’s disruptions—described by police as “another step closer to terrorism”—are the fourth straight day of upheaval in Hong Kong, where for the past five months protesters have been waging an increasingly violent campaign for greater political freedom, and, for some, autonomy or secession from China. Hundreds have been arrested in the past week alone and scores hospitalized—at least three critically—in unrest that has flared up across the enclave.

In a meeting of the Legislative Council Thursday, Hong Kong’s second-highest ranking official, Chief Secretary Matthew Cheung, cast doubt on the viability of local elections in 10 days’ time.

“How can you vote when there’s neither bus nor MTR, and when projectiles are being hurled?” he reportedly asked lawmakers.

The deteriorating situation has prompted the government to draft a batch of correctional services officers as special constables, in order to relieve the burden on a desperately stretched police force.

“The ongoing riots over the past few months, with their massive scale, simultaneous occurrence in various districts and grave severity of violence, make it necessary to strengthen the support for the police’s front-line officers,” the government said in a statement.

At a press conference Thursday, the police redoubled their demand for Hong Kong’s democracy movement to disown its violent, radical wing.

Said Chief Superintendent John Tse: “You cannot fight for freedom of speech by silencing people who disagree with you. You cannot fight for democracy by terrorizing the public to force others to support you. You cannot condemn brutality by brutalizing people who hold different views to yours. And if you still refuse to cut ties with rioters, if you are still looking for excuses to defend rioters, you are indeed an accomplice.”

—With reporting by Laignee Barron / Hong Kong

Get The Brief. Sign up to receive the top stories you need to know right now. Please enter a valid email address. Sign Up Now Check the box if you do not wish to receive promotional offers via email from TIME. You can unsubscribe at any time. By signing up you are agreeing to our Terms of Use and Privacy Policy . This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply. Thank you! For your security, we've sent a confirmation email to the address you entered. Click the link to confirm your subscription and begin receiving our newsletters. If you don't get the confirmation within 10 minutes, please check your spam folder.

Contact us at letters@time.com.