That came as about 50 students boycotted classes and joined a peaceful sit-in at a car park outside the school. Flanked by pupils from other schools, they chanted “Tsang Chi-kin, add oil”, and “Ho Chuen Yiu, add oil”, and folded origami cranes sending the teen blessings.

Video footage posted online showed a group of protesters chasing a police officer with a long shield, pinning him to the ground and beating him.

Another riot policeman rushed forward with his service revolver pointed at the protesters.

The policeman with his gun drawn was seen clashing with Tsang, who swung his rod at the officer, at which point he opened fire.

Solicitor Ng Gene-bond, who is assisting Tsang, said: “My client had undergone surgery and is now still receiving treatment in the intensive care unit. At the moment his life is not in danger.”

Ng declined to reveal further details.

At least twice on Wednesday morning police officers visited Queen Elizabeth Hospital’s intensive care unit, where Tsang was staying in. Each visit lasted around five to 10 minutes.

Chan, 16, a Form Five student who declined to give his full name, said Tsang had a “high political awareness” and was “active” in voicing his political views.

“He’s very passionate and always participates actively,” Chan said, adding the school did not offer enough support for students with emotional needs.

The school’s principal, Tse Yun-ming, expressed sympathy towards Tsang’s family, and said the college had been providing support to them.

Tse said he was saddened by the news of the shooting, and the school had activated its crisis management team, which includes providing emotional support for students.

“It would be good if everyone could give the school some space,” he said, but declined to comment on whether the school would condemn police.

Tse later had an hour-long meeting with school alumni, which ended in acrimony after Tse and two vice-principals faced pressure to condemn the officer’s use of force.

Student in stable condition after being shot with live round by police

A 35-year-old alumnus, surnamed Yeung, said Tse only said he would consider it.

She also said vice-principal Ho wai-Hung had told them, “violence cannot solve any problems”, and compared the relationship between Beijing and Hong Kong to that of parents and children, urging that “children should not smash up things at home even if they are discontented”.

“We are disappointed,” Yeung said. “That’s trash talk. I understand the stance of the school and never expect the school to say anything anti-Beijing.

“But if the school fails to stand up against violence, police could escalate force in the future.”

Yeung said she had watched the footage many times and believed the shooting was more than an act of defence.

“He held the gun for too long. It is more like a lethal attack. The student was just lucky to survive,” Yeung said. “For me, a condemnation of force is far from enough. The officer should be accountable through legal means.”

Hong Kong police ‘overwhelmed’ as protesters unleash new level of violence

Another alumni, wearing a Guy Fawkes mask, said two other former pupils who were with Tsang on Tuesday felt guilty for failing to protect him.

“If there were enough comrades on the front line, they believed there was a chance to save Tsang,” the alumni said.

“War has started,” he said, adding those who had stayed at home should take to the streets and those peaceful protesters should consider helping out on the front line.

Kwan Long-ching, 17, a Form Six student from nearby Liu Po Shan Memorial College in Tsuen Wan, said he believed the shooting was unreasonable, although he did not completely agree with protesters attacking police.

Kwan said he was terrified by Tuesday’s incident.

“The next person who may get shot could be me or any of my friends,” he said.

Meanwhile, former Hong Kong leader Leung Chun-ying, now vice-chairman of the Chinese People’s Political Consultative Conference, wrote five Facebook posts on the shooting incident.

In his last post, Leung said: “We should not only ask if the officer should have fired, but also if the students committed serious crimes when they took part in riots and attacked police.

“The principal should immediately remove the student status of these thugs as punishment. If the principal is afraid that others will cause damage to the school, then he should resign.”

Leung also later sent a letter to the school, reiterating the call.

The Hong Kong Professional Teachers’ Union issued a statement on Wednesday evening, blasting Leung’s act as a “blatant political interference on a school”.

It also said many teachers and principals from other schools had expressed their anger at Leung’s remarks. The union urged all sectors in the city to give room and time for the school concerned to deal with its students who require emotional support.