Hong Kong police said in a media briefing on Sunday that 63 people, aged 13 to 36, were arrested at Prince Edward subway station and Mong Kok subway station on Saturday night. They were arrested on suspicion of illegal assembly, possessing explosives as well as offensive weapons.

The 13-year-old was found to have petrol bombs and lighters. 

The police made a series of arrests at several locations between Saturday night and the early hours of Sunday as they vowed to protect the city from violent protesters.

At Causeway Bay and Sai Wan, 11 others were apprehended for possession of offensive weapons and fake press passes.

The police strongly condemned the vandalism at the two stations.

"We will by no means allow the escalation of reckless violence," Yu Hoi-kwan, senior superintendent of Police Public Relations Branch said at a press conference on Sunday.

"Hong Kong has gone through a catastrophe last night," the spokeswoman said, just hours after radical protesters set ablaze public property, vandalized government buildings and paralyzed traffic.

The police had banned the application of a public procession on the Hong Kong Island on Saturday to ensure the safety of residents and public order after several similar events turned extremely violent since early June.

However, protesters on Saturday defied the police ban by occupying downtown roads. During their march, some radical protesters smashed traffic lights, and dismantled roadside railings to set up barricades to confront the police.

Black-clad rioters who wore masks and helmets attempted to storm into the headquarters of the Hong Kong Special Administrative Region (HKSAR) government and the Legislative Council, used sling shots to fire petrol bombs and other objects into the buildings before they went on to set fires on a main street near the Hong Kong police headquarters.

Yu confirmed that two police officers fired two warning shots into the air Saturday night in Victoria Park when they were besieged and attacked by violent protesters and their lives were under threat.

She stressed that before the officers fired the warning shots, they had manifested their identities as police officers and had issued clear warnings, thus such decisions are correct and reasonable.

"The behaviors of the rioters were horrific," Yu said.

"Breaching the law is breaching the law. Any appeal should not be the excuse for breaking the law. The police has the capability and determination and will try every effort to bring those outlaws to justice and let the society return to normal."

(With input from Xinhua)