Hong Kong office workers and schoolmates of a teenage demonstrator shot at close range by a police officer have rallied to condemn police tactics and demand accountability.

The shooting during widespread anti-government demonstrations on China’s National Day was a fearsome escalation in Hong Kong’s protest violence.

The 18-year-old, who was shot in the chest on Tuesday, is the first known victim of police gunfire since the protests began in June. He is in hospital where his condition was described by the government as stable.

Police fire tear
Police fire tear gas (Kin Cheung/AP)

The officer fired as the teenager, Tsang Chi-kin, struck him with a metal rod. The officer’s use of lethal weaponry is sure to inflame widespread public anger about police tactics during the crisis, widely condemned as heavy handed.

“The Hong Kong police have gone trigger-happy and nuts,” pro-democracy legislator Claudia Mo said on Wednesday.

After viewing a video of the shooting, Ms Mo said: “The sensible police response should have been to use a police baton or pepper spray, etc, to fight back. It wasn’t exactly an extreme situation and the use of a live bullet simply cannot be justified.”

More than 2,000 people chanted “No rioters, only tyranny” as they filled an open-air stadium near Mr Tsang’s school in Tsuen Wan district on Wednesday night.

Hong Kong Protests
Protesters in Hong Kong (Vincent Yu/AP)

Many held posters reading “Don’t shoot our kids” and held an arm across their chest below their left shoulder — the location of Mr Tsang’s gunshot wound.

Several other peaceful rallies were held elsewhere, with protesters vowing not to give up their fight for more rights including direct elections for the city’s leaders and police accountability.

But pockets of protesters vented their anger. Black-clad youths smashed ticket machines and vandalised facilities at two northern subway stations.

In Tsuen Wan, hundreds marched along the streets. Some smashed Bank of China ATMs and others removed metal railings and dug up bricks from pavements to build barriers, blocking traffic.

Hong Kong Protests
Residents of Tsuen Wan gather at an open air stadium (Vincent Thian/AP)

Earlier on Wednesday, hundreds of people, including students, sat crossed-legged outside Mr Tsang’s school chanting anti-police slogans. One held a hand-written message condemning “thug police”.

Schoolmates said Mr Tsang loves basketball and was passionate about the pro-democracy cause. A student who wore a Guy Fawkes mask and declined to be named because of fear of retribution said Mr Tsang was “like a big brother” to him and other junior students.

“During the protests, we would feel safe if he is around because he was always the first to charge forward and would protect us when we were in danger,” the student said.

“I vividly remember him saying that he would rather die than be arrested. What an awful twist of fate that it was he of all people who was shot by the police.”

Many students felt that firing at Mr Tsang’s chest, close to his heart, was an attempt to kill him. Police said he has been arrested despite being in hospital and authorities will decide later whether to press charges.

Hong Kong Protests
A protester outside Mr Tsang’s school (Vincent Yu/AP)

More than 1,000 office workers skipped their lunch to join an impromptu march in the city’s business district against the police shooting. Dozens of black-clad protesters also protested at a luxury mall in Kowloon district.

Police have defended the officer’s use of force as “reasonable and lawful”. Police Commissioner Stephen Lo said the officer had feared for his life and made “a split-second” decision to fire a single shot at close range.

Deputy Police Commissioner Tang Ping-Keung said the officer had fired at his chest to immobilise the youth quickly.

Mr Tang denied that police had been given permission to shoot to kill. He said the officer’s action was in line with international procedures, but that police would mount an in-depth investigation.

Hong Kong’s government said the widespread rioting on Tuesday was “planned and organised” and called on parents and teachers to help restrain young protesters.

Videos on social media of the shooting showed a dozen black-clad protesters throwing objects at police and closing in on a lone officer, who opened fire as the masked teenager came at him with a metal rod.

The protester toppled backward on to the street, bleeding from below his left shoulder.

As another protester rushed in to try to drag away the wounded youth and was tackled by an officer, a petrol bomb landed in the middle of the group of officers in an explosion of flames.

Riot police fired tear gas in at least six locations on Tuesday and used water cannons in the business district, as usually bustling streets across the city became battlefields.