The education department bowed to pressure from teacher groups who criticised Chief Executive Carrie Lam's government for not closing schools on safety grounds. Multiple schools said classes were suspended while the education board said parents could choose whether to send children to school. Photographs circulated on social media of school girls in uniform being lined up against a subway wall by riot police conducting identity checks. Beijing's liaison office in Hong Kong called for Lam's government and police to take "all necessary means to forcefully crack down on various acts of violence and terrorism”. In the square outside the Hong Kong stock exchange, riot police moved in with batons to arrest office workers. Four Chinese University of Hong Kong students charged with rioting appeared in court, while a fifth remained in hospital.

Roads outside the Baptist University were barricaded with bricks to slow any police charge onto the campus. Professor Rocky Tuan, president of the Chinese University of Hong Kong, centre, arrives to negotiate with students and police. Credit:AP Hong Kong media reported mainland students at City University dormitories had been advised to go to the mainland as a precaution as tensions between police and protesters escalated. Lawyers for the students' association at the Chinese University sought a High Court injunction to stop police returning to the university campus in the New Territories, with a hearing due Wednesday evening. A petition signed by more than 600 Hong Kong and international academics criticised the police storming of the university campus and use of tear gas and rubber bullets. The president of the Chinese University of Hong Kong, Rocky Tuan, was hit with police tear gas on Tuesday night while attempting to negotiate for calm between police and students as a day of tense stand-offs on campus erupted into a battlefield at night.

Tuan, a world-renowned biomedical scientist, was 50 metres from police as they opened fire with rubber bullets and tear gas and reportedly shouted at him that it "isn't the time to negotiate". Multiple students were hit in an initial barrage at 7.30pm that lasted 10 minutes, Radio Television Hong Kong reported. But clashes between students and police continued for another three hours, turning a bridge on the outskirts of the campus into a battlefield. Students try to clear the tear gas canisters fired by riot police on the sports track during a confrontation in the Chinese University in Hong Kong. Credit:AP The university's pro vice-chancellor, Dennis Ng, arrived wearing a gas mask and yellow helmet and shouted at police with a loud speaker to stop firing. Ng said he had struck a deal with the police commander for the barrage to stop, but police continued to fire. Protesters were later shown being carried out on stretchers from the university gym where a makeshift medical centre was created.

Tuan had sought to negotiate a deal for the police to withdraw from the university campus in return for the university sending security guards to protect the bridge. Protesters had thrown bricks and objects onto a highway below from the bridge, amid a general strike across the city designed to disrupt transport and traffic. Medical workers move an injured student following clashes with police at the Chinese University in Hong Kong. Credit:AP The students had demanded Tuan also call for the release of students arrested on campus earlier in the day, with at least one reported to be facing a charge of rioting which could mean up to 10 years in jail. Tear gas had billowed across the university's sports grounds through the afternoon as riot police made repeated incursions into the campus.

Tuan had stridden past the blazing wreck of a car towards police front lines to negotiate.

Frontline police lost patience and opened fire. Students with umbrellas continued to push forward against police lines on the bridge, throwing Molotov cocktails and throwing back police tear gas canisters. Loading Injured protesters were dragged back from the frontline by first aid workers. Fire engines arrived at the university to put out fires lit by protesters. The campus is up a hill and remote from the nearest town, Shatin. The police water cannon arrived on the bridge at 10pm to repel protesters with high pressure sprays of blue dye.

Shortly afterwards police issued a statement saying police and the school were "arranging a retreat to stop the stand-off. The police appeal to the protesters to stop charging". By 10.30pm the university's former president, Joseph Sung, a prominent Hong Kong doctor, arrived in gas mask and goggles to talk to students and seek a truce. Sung told them three students arrested had been granted bail. A group of academics from several universities had earlier decried the police incursions on to multiple university campuses on Tuesday, saying these were places where thousands of students lived and studied and were permitted to hold gatherings. Fifty people were hospitalised on Tuesday. There were unconfirmed reports that injured students at the Chinese University could not reach hospitals. One local politician estimated a thousand tear gas canisters had been fired at the campus by police.

Social media posts showed people on motorbikes and bicycles carrying supplies for the protesters up the hill to the campus after police had retreated. At a police press conference on Tuesday afternoon senior superintendent Kong Wong-Cheung had warned “Hong Kong’s rule of law has been pushed to the brink of total collapse” in recent days. But a one-time rival to Carrie Lam for the Hong Kong chief executive position, former finance secretary John Tsang, said in a radio interview there needed to be an independent inquiry into the protests and how they were being policed to “find out the truth”. Tsang said there was a power imbalance between the government and the protesters and the government needed to de-escalate the force it was using in the community and “step back a bit”. Police had arrested 287 people on Monday, the highest number in a single day since the protests started in June. They said 60 per cent of those detained were university students.