HONG KONG • He was the kind of 18-year-old high school student who was more interested in basketball than studying; one of four student vice-presidents who classmates say never showed an interest in politics until this year.

Friends described him as charming and funny, with long hair that he sometimes kept in a ponytail. Just another student. Not an icon. Not a symbol. Not a lightning rod.

But on Tuesday, the student, Tsang Chi Kin, became all of those things when he was shot by police during a day of violent protests in Hong Kong.

The shooting - the first time police officers in the territory used a live round against a demonstrator in nearly four months of protests - represented a new escalation in the violence that has roiled the city.

Police said he was shot in the shoulder. But various media reports said he was shot in the chest. The hollow-point bullet narrowly missed his heart and spine, but pierced a lung.

As of Wednesday, he was in intensive care but in stable condition, according to the Hospital Authority.

"He is a very fortunate person, when you look at the organs that are there," said Dr Darren Mann, a Hong Kong surgeon and expert in ballistic injuries.

The teenager was one of thousands of protesters who fanned out across Hong Kong on Tuesday and battled the police for hours through fogs of tear gas. The street brawls started just hours after Chinese President Xi Jinping presided over a carefully choreographed military parade in Beijing to celebrate 70 years of Communist Party control.

The shooting, which has been replayed for hours on local television news channels, has divided the city.

Supporters of the pro-democracy protests said the episode epitomises all that is wrong with a Hong Kong government that has prioritised brute force over genuine political dialogue.

The movement's critics, on the other hand, said the shooting highlights the shameful excesses of a youth-led movement that has increasingly resorted to vandalism and attacks on police officers.

Seven friends of Tsang discussed the young man's activities, but insisted on anonymity because they feared retaliation by police or others if their identities were known. Tsang, they said, was barely aware of politics until June, when the first major protests against a Bill that would have allowed Hong Kong residents to be extradited to the mainland for trial convulsed the city.

The young man, they said, became more committed to the movement, regularly attending protests, participating in political discussions online and advocating for greater democracy in Hong Kong.

Starting this summer, Tsang played a leading role in a group of a dozen protesters from several high schools who attended protests together, his friends said. He was with half a dozen people at the protest on Tuesday in Tsuen Wan, a working-class neighbourhood of residential tower blocks, when he was shot.

Police Commissioner Stephen Lo said the officer involved had acted in a "legal and reasonable" manner, having given a verbal warning before opening fire.

Tsang has been charged with rioting, which carries a maximum 10-year sentence, and assaulting a police officer. He was not able to attend court, but about 200 supporters turned up to watch the proceedings.

Mr Joseph Cheng, a retired professor of political science at the City University of Hong Kong, said the shooting could turn Tsang into a powerful symbol for activists on either side of the protests. In less than 24 hours after the shooting, he was being hailed as a hero and derided as a thug.

NYTIMES