- Video report by ITV News Asia Correspondent Debi Edward
An 18-year-old student remains in a critical condition after being shot in the chest by police at close range.
It was the first time a protester had been shot with a live round since protests in Hong Kong began in June, with tensions already fraught between activists and authorities.
Students at the Tsuen Wan Public Ho Chuen Yiu memorial college - which the teenager attended - called police “murderer” on Wednesday. They chanted anti-police slogans and demanded accountability.
Sitting crossed-legged, some held an arm across their chest to below their left shoulder - the location of the teenager’s gunshot wound.
One held a hand-written message condemning “thug police”.
Tuesday's protests were designed to mar China's National Day, marking 70 years of Communist rule.
Pro-democracy politician Claudia Mo said: "The Hong Kong police have gone trigger-happy and nuts."
Having repeatedly viewed video of the shooting, Ms Mo said: “The sensible police response should have been using a police baton or pepper spray etc, to fight back.
“It wasn’t exactly an extreme situation and the use of live bullet simply cannot be justified.”
Police Commissioner Stephen Lo defended the action as "reasonable and lawful", saying the officer feared for his life and had no other choice.
"The officer was under attack, his life was threatened," he said. "He made a very quick decision and shot the assailant. I believe it was his best judgment at the time."