Hong Kong police have fired pepper spray at protesters angry about an extradition bill that would allow people to be sent to mainland China for trial.
Tens of thousands of demonstrators, most of them young people dressed in black, had gathered peacefully outside government buildings in the Chinese-ruled city before tempers flared, with claims some threw bottles at officers.
Rubber bullets were also used to try and keep people back as the protests turned to chaos, with some campaigners charging officers with umbrellas.
Ambulances were seen heading towards the crowds as a police chief warned protesters they – must stop the violence, and urged residents to stay away from the area.
Riot police with shields and batons have pushed back against people attempting to storm past barricades to get to into Hong Kong’s government headquarters.
Protesters have scattered from some areas as claims compressed water was also deployed by officers trying to protect official buildings.
The demonstrations forced the delay of a legislative debate over the controversial bill, which would allow criminal suspects in Hong Kong to be sent for trial in mainland China.
The protests are a challenge to China’s ruling Communist Party and President Xi Jinping, who has previously said he would not tolerate Hong Kong being used as a base to challenge the party’s authority.
China’s central government firmly supports the planned extradition law, the foreign ministry reiterated on Wednesday.