A 24-year-old Hong Kong man with a triad background has been charged with two counts of arson after allegedly throwing two gasoline bombs on Friday – one at a police car outside the Police Force Headquarters in Wan Chai and the other near Happy Valley Police Station.

The suspect surnamed Chong, said to be a triad member active in Eastern District on Hong Kong Island and Kowloon’s Tsim Sha Tsui, appeared at the Eastern Magistrates’ Court on Monday for his first mention, Headline Daily reported.

Chong was among several men aged between 22 and 60 who were arrested. All were released on bail but need to report to the police early next month.

The first firebomb was thrown at a police vehicle at about 3:30am on Friday and the second was thrown outside the Happy Valley police station at about 4pm.

Dashboard-camera footage has surfaced on social media of one incident. It shows a man in a black jacket with a cap standing next to a black Mercedes-Benz who was seen wandering on Arsenal Street, in front of the Police Headquarters.

He ignited the gasoline bomb and threw it at a police car driving along Jaffe Road and making a slow right turn. Flames were seen near the police car and broken glass at the scene. The man fled by car. Four police officers inside the car were not hurt. They did not pursue the suspect – stopping their car alongside the road because of concern it could catch fire.

The second firebomb was also thrown by a man in a black Mercedes-Benz while it passed Happy Valley Police Station. The bottle of gasoline hit a corner of a nearby fence. Parts of the station wall and floor were blackened, Apple Daily reported.

After checking surveillance footage, police said the suspect had been driving the black vehicle with covered plates. He allegedly got out of the car, threw the firebomb before getting back into the vehicle and driving away down Sing Woo Crescent.

The Mercedes-Benz was later intercepted by police near King’s Road in North Point. The suspect ran into a nearby building but was caught by the police later.

Initial investigations found that the suspect bought gasoline at a filling station then bottles of beer at convenience stores two hours before the attacks.

The bomb attacks happened two days before the rally against the controversial extradition-law amendment in the city on Sunday but police believed there was no connection between the two incidents, Radio Television Hong Kong reported.

Rally organizer The Civil Human Rights Front raised concerns that the firebomb incidents might intimidate potential demonstrators and affect the turnout for the rally.

It turned out 1.03 million people participated in the rally.