(Bloomberg) -- For a moment Tuesday night, it looked like days of intense sparring between riot police and students at one of Hong Kong’s top universities might finally end.

Black-clad students held back their petrol bombs and stopped building barricades that disrupted traffic near the Chinese University of Hong Kong. Police halted tear gas and rubber bullets. Vice Chancellor Rocky Tuan pushed toward the police lines to strike a truce.

Then, someone flashed a laser pointer at some officers. Police fired back with tear gas. Tuan was caught in the noxious fumes.

“The deal was being confirmed by both sides,” said Kai Chi Leung, who teaches China studies at CUHK and was among a group of university staffers involved in the negotiations. “Then chaos broke out.”

While Hong Kong’s eight government-subsidized universities -- like their counterparts around the world -- have a long history of political activism, the protests gripping Hong Kong for the past five months have brought unprecedented battles onto the campus green. Several campuses have seen extended sieges in recent days as anger flared over the Nov. 8 death of a Hong Kong University of Science and Technology student who had fallen near police efforts to disperse a protest.

Read live updates from Hong Kong

Demonstrators have obstructed roads near campuses at top schools including the University of Hong Kong, Hong Kong Baptist University, The Hong Kong Polytechnic University, and City University of Hong Kong. Some demonstrators cut down trees to block thoroughfares, threw furniture from bridges and pulled up paving bricks to use as projectiles.

“I don’t see how I can teach class pretending everything is normal at this point,” said Lokman Tsui, a CUHK School of Journalism and Communication assistant professor. Sean Kenji Starrs, an assistant professor of international relations at City University, said his campus had turned into “a battleground.”

Classes Suspended

On Wednesday several universities said they would halt classes for much of the week and called off graduation ceremonies. Baptist University said it canceled on campus classes for the final two weeks of the semester. CUHK said it had suspended all classes for the remainder of the semester.

With passions running hot, university officials have been caught between the government’s demands that they discourage protests and the expectations of support from the city’s 324,000 college students. Students from mainland China have found themselves outnumbered amid a sudden upsurge of anti-mainland sentiment, with police sending a boat to ferry some trapped on the CUHK campus to a safe location.

Worsening Hong Kong Violence Could Embolden Hawks in China

Over the past week, police have stormed many of the campuses, in some case firing tear gas. Police said in a statement Tuesday that officers had “no choice but to deploy the minimum necessary force,” noting that protesters had thrown bricks, petrol bombs, arrows and a signal flare at police officers, endangered pedestrians and hampered emergency services.

“The campus is not a place out of law,” Chief Superintendent of Public Relations Tse Chun-chung told reporters Wednesday. Officials said during the same briefing that students comprised 1,500 of the more than 4,000 people arrested since protests began in June, with some 850 of them university students.

Taking Action

The images of riot police pouring into college campuses also drove some people to action. Ms. Choi, a final year student at CUHK, was out on the streets of the Central business district Tuesday afternoon when she heard of the police action at her school.

She decided to spend her cash on first aid supplies and food and found a volunteer driver to transport her back to campus, where she arrived around 7 p.m. “This is the last resort of a place of safety. We expect to be protected on campus,” she said.

The Red Cross of Hong Kong dispatched a team to CUHK, where they said they handled 110 cases. By Wednesday morning, hundreds of protesters had returned to their barricades at CUHK, where they had stockpiled bricks and petrol bombs.

CUHK Student Union President So Tsun Fung applied for a court injunction to stop police from entering campus and deploying “crowd control” measures without permission. The court was expected to consider the request at 5 p.m. hearing Wednesday.

The Hong Kong Police Gunshot That Unleashed a Day of Mayhem

When a reporter approached the administration’s office on Wednesday morning, Professor Ko Wing Hung, dean of students at Chung Chi College, answered the door and said the administration was discussing “the security situation, how to maintain food supply and how to meet the needs of non-local students.”

In a statement Wednesday, the university said it was “saddened” by the number of staff and students injured in the melee and urged a halt to “all forms of violence.” “The university sincerely appeals to all members of the University and different sectors of the community to give us time and space for a prompt restoration of order and function on campus,” it said.

Young Activists

Universities in the former British colony have been hot beds of activism since the University of Hong Kong was founded in 1911 -- first as centers of Chinese nationalism, then as incubators for democratic views. Students unions at various universities were active in the bloody leftist riots that rocked Hong Kong in 1967 and helped lead the Umbrella movement in 2014.

Professors at a number of universities say they’ve tried to be understanding and accommodate students who miss classes to protest. In some cases, they’ve decided not to take attendance, provided recordings of classes and offered counseling.

China Signals Greater Role in Hong Kong’s Schools, Elections

Many professors have channeled the anger, divisiveness and attention to turn their classrooms into living laboratories for subjects like politics, journalism and the arts. “Class discussions have completely changed by students who now voice strong opinions, with the protests catapulting them to take sides,” said Ekkehard Altenburger, an assistant professor of sculpture at the academy of visual arts at Baptist University.

CUHK’s Vice Chancellor Tuan in October posted a 2,000-word open letter describing a series of meetings he held with students, in which a female student claimed she was sexually assaulted in a darkened body-search room at a detention center near the mainland Chinese border and wasn’t the only one who “suffered sexual violence.” Police pledged to investigate the allegation.

The vice chancellor apologized to students for not doing enough and said he recognized the “pain and suffering of the students, how they were driven to a state of hopelessness,” offering to help provide legal and other aid.

Mainland Students

The unrest has caused some mainland students, who make up roughly 10% of those enrolled at eight leading universities, to flee across the mainland border to Shenzhen, helped by Chinese nationals and the Communist Party’s Youth League. CUHK undergraduate Leo Lin left his dormitory at 4:30 a.m. Wednesday morning after seeing police firing tear gas and student protesters throwing petrol bombs for hours, joining what he says are thousands of other students who have fled to the mainland.

How Fake News and Rumors Are Stoking Division in Hong Kong

“I didn’t want to leave at the beginning. I wanted to go to classes today,” said Lin, 19. “But the atmosphere deteriorated quickly, and I suddenly felt the urge to leave.” he said.

Now, the question is whether classes will resume anytime soon.

“I’m not optimistic,” Ivan Choy, who has taught politics and government at CUHK for 16 years, said, adding that he’s from numerous students that they’re traumatized. “We’ve never seen this psychological or emotional toll on students at such scale.”

--With assistance from Blake Schmidt, Natalie Lung and Jinshan Hong.

To contact the reporters on this story: Shelly Banjo in Hong Kong at sbanjo@bloomberg.net;Aaron Mc Nicholas in Hong Kong at amcnicholas2@bloomberg.net

To contact the editors responsible for this story: Daniel Ten Kate at dtenkate@bloomberg.net, Brendan Scott, Karen Leigh

©2019 Bloomberg L.P.