More than 40 radical protesters were arrested in overnight police operations in Hong Kong, according to a police spokesperson at an early Sunday morning press conference.

Senior Superintendent Yu Hoi-kwan said that 40 protesters were arrested at Prince Edward MTR station on suspicion of committing crimes including taking part in an unauthorized assembly, criminal damage and obstructing police officers' execution of duties.

A pair of police officers fired two warning shots when they were assaulted by radical protesters at Victoria Park on Hong Kong Island, Yu added.

The spokesperson stressed that the officers' use of force was "rightful and reasonable" .

Divisional Commander (Hong Kong Central) of the Fire Services Department Yeung Kai-wang told the press conference that there were six reported cases of fires on Saturday, two of them outside the Central Government Offices and the Police Headquarters.

Violence erupted in Hong Kong for yet another day on Saturday as radical protesters set fires and attacked police officers with gasoline bombs, bricks, sharpened poles and projectiles.

Police deployed tear gas and water cannons to disperse the mob after repeated warnings were ignored.

Yu said that the protesters' acts of violence were appalling and posed a grave threat to public safety.

She urged the public to reject violence, adding that the police have the determination and capability to combat violence and to restore law and order.