Baton-wielding Hong Kong riot police fired warning shots and pepper spray early Tuesday after a riot erupted in a busy district when officials tried to shift illegal hawkers on Chinese New Year.
Television footage showed one officer pointing his gun at crowds of protesters on the streets of Mongkok who hurled bricks, bottles and pieces of wooden pallets at police in the worst clashes since pro-democracy demonstrations in late 2014.
Police fired at least two warning shots in the air, multiple news outlets reported, while footage showed protesters removing bricks from pavements, charging police lines with homemade shields and setting rubbish on fire in the middle of the road.
The street battles erupted after officials tried to move illegal food sellers while protestors, including members of radical "localist" groups, tried to defend the hawkers whom they say add to the festive atmosphere.
"There was a riot in Mongkok in the early hours of today. A few hundred mobs attacked police officers and media," Hong Kong leader Leung Chun-ying told media Tuesday.
"They committed acts of arson, threw bricks and other objects at police officers, including those who had already been injured and were lying on the ground," Leung said, adding that the government "strongly condemns such violent acts".
Footage from Cable Television News showed police and protesters still in a stand-off as day broke while the city's subway operator MTR closed Mongkok station due to "public activities".
TVB news footage showed protesters harassing and attacking their cameraman who sustained injuries to his hand.
Police said they acted after crowds ignored calls to disperse.
"To ensure public safety and public order, police took resolute actions, including using baton and pepper spray, to stop the unlawful violent acts," a police statement said, without mentioning any warning shots.
Police said three men were arrested and three officers were injured and had been sent to hospital for treatment while Hong Kong broadcaster RTHK later reported dozens had been arrested.
Reports said one of those arrested was Edward Leung, a "localist" candidate for an upcoming by-election on February 28.
The so-called "localists" seek to heavily restrict Beijing's influence in the city and some even want an independent Hong Kong.
The clashes come at a time when the fate of five booksellers, believed to have been detained in mainland China after disappearing late last year, has put residents on edge over concerns the semi-autonomous city's freedoms are being eroded.
Tensions still remain high between protesters and police who used tear gas to disperse protesters at the beginning of mass rallies for fully free elections in late 2014 that lasted more than two months and paralysed parts of the city.