Police increased security around Hong Kong and its university campuses Wednesday as they braced for more violence after sharp clashes overnight with anti-government protesters.

Many subway and rail stations were closed after the protesters blocked commutes and vandalized trains. Classes were suspended at universities, and parents of school students advised they could keep their children home.

Police and protesters battled on multiple fronts overnight at the Chinese University of Hong Kong. Gasoline bombs and fires lit the nighttime scene, and the situation remained tense in the morning and early afternoon.

A police official warned protesters were carrying out “insane acts” and Hong Kong was on the brink of a total breakdown after more than five months of protests.

Students stand near a fire and a charred vehicle during a faceoff with riot police at the Chinese University in Hong Kong on Tuesday. (Kin Cheung/The Associated Press)

“Our society has been pushed to the brink of a total breakdown,” Senior Police Supt. Kong Wing-heung said late Tuesday.

He said Hong Kong’s mass transit system and subway, known as MRT, was under stress from acts of violence and vandalism.

‘Insane acts’

“Masked rioters have lost control and committed insane acts like throwing trash, bicycles and large objects onto MTR tracks, hanging trash on overhead power lines,” he added.

Groups of riot police were deployed around central Hong Kong and its outlying territories to try and contain new violence, even as students at the Chinese University — located in the outskirts of the sprawling metropolis — prepared for new clashes with police. Many were armed with gasoline bombs while some carried bows and arrows.

WATCH: See scenes from Hong Kong as clashes escalate

Protesters light fires, police launch tear gas as tensions mount. 0:57

The university’s student union president, Jacky So, appealed for an injunction with the High Court to ban police from entering the campus without a warrant, or the school’s approval. Police had entered the campus and fired tear gas and used a water cannon late Tuesday.

The injunction would also block police from using crowd control weapons, such as tear gas and rubber bullets at the university. A decision is expected late Wednesday.

Religious leaders appeal for restraint

The city’s religious leaders appealed Wednesday for an end to the violence and called on both police and protesters to show restraint.

“At this very critical point, the people of Hong Kong must unite and say no to violence,” said a statement issued by the leaders of Hong Kong’s six major religious groups.

The standoff between students and police brought traffic to a halt. (Tyrone Siu/Reuters)

A statement from the Chinese government’s liaison office in Hong Kong said that the semi-autonomous territory is “slipping into the abyss of terrorism.” It called the setting of a man on fire an act of “flagrant terrorism.”

On Monday, a police officer drew his gun during a struggle with protesters, shooting one in the abdomen. In another neighbourhood, a 57-year-old man who was defending China was set on fire after an apparent argument.

WATCH: Hong Kong police shoot protester as chaos erupts across city

Protesters rallied once again in Hong Kong on Monday, as the Chinese-ruled region spiralled into rare working-hours violence in its 24th straight week of pro-democracy unrest. 0:51

The man remained in critical condition, while the protester had his condition upgraded to serious from critical.

Recent weeks have been marked by escalating vandalism of shops linked to mainland China and train stations, and assaults by both protesters and pro-Beijing supporters.

3,500 arrested

Police have arrested more than 3,500 people since the movement began in June.

The protests began over a proposed law that would have allowed criminal suspects to be extradited to mainland China, where they could face opaque and politically sensitive trials.

Activists saw the bill as another sign of an erosion in Hong Kong’s autonomy and civic freedoms, which China promised would be maintained for 50 years under a “one nation, two systems” principle when the former British colony returned to Chinese control in 1997.

Hong Kong leader Carrie Lam eventually withdrew the bill but has insisted the violence stop before any further political dialogue can take place.