Riot police have fired tear gas and rubber bullets in scenes of “utter bedlam” as masked protesters march through central Hong Kong.
The demonstrators, many wearing gas masks and helmets, are marching against what they say is excessive police force.
Sky’s Asia correspondent Thomas Cheshire said it was chaos and that a small group of protesters look prepared for a fight with authorities.
The police “are throwing everything they have at them”, said Cheshire, adding that officers are displaying warning signs before they fire the gas.
Protesters – many with umbrellas, a few with weapons such as hockey sticks – have been responding by throwing bricks, eggs and other objects.
Cheshire said police had suddenly sprinted at full pace towards the protesters in a “brutal” attack to try and finally end the protest.
“They tore into them , they lay into them,” he said.
Police have urged people to stay inside and close their windows due to the tear gas.
The unrest started weeks ago, initially over anger about a planned extradition law that would allow people to be sent to the Chinese mainland for trial.
But protesters are now venting their anger over the police’s use of force to break up a demonstration a week ago.
Some people were also beaten up by suspected triad gang members while leaving that demo. Protesters accuse police of reacting slowly to that violence.
More unrest on Saturday saw at least two dozen people injured after police again used tear gas, while protesters threw bottles and rocks.
As well as the scrapping of the extradition bill, their demands now include the resignation of Hong Kong’s leader, Carrie Lam, and an investigation into the police’s use of force.
Hong Kong authorities had tried to ban protesters from the streets on Sunday but it appears to have had little effect.
A push for full democracy is underlying the protests – the city’s leader is chosen by a pro-Beijing dominated committee, rather than direct elections.
Britain handed the territory back to China in 1997 with assurances it would operate under a “one country, two systems” formula.