Police arrested four men after a bloody knife attack and a car crash when fighting erupted between rival triad groups in the New Territories late on Thursday.

About 30 people with triad backgrounds gathered in a restaurant in Lakeside Garden on Chui Tong Road in Sai Kung at 11pm to celebrate the birthday of a leader of Wo On Lok, one of the main triad groups in southern China, news website HK01.com reported. The group was attacked by a gang of four knifemen wearing face masks, believed to be from the Wo Shing Wo triad.

The attackers stabbed several people, then tried to escape. However, followers of the Wo On Lok group chased after them and fought back with rubbish bins or sticks they grabbed on the roadside.

The attackers got into a grey seven-seat van but the vehicle was intercepted in a carpark with Wo On Lok members hurling rubbish bins at the car, according to a video that surfaced online.

The 3-minute video showed the van being rammed by a truck and another vehicle at least four times. The attackers left the vehicles and fled on foot.

https://www.youtube.com/watch?v=-XB2Zt3kn_8

Police arrived and arrested the driver plus three men armed with or accused of using knives – one found on a sampan near Chui Tong Road waterfront, one in a public toilet for disabled people and one on the roadside, Oriental Daily reported.

A man from Wo Shing Wo group was stabbed and sent to the hospital for medical treatment of his injuries.

Kowloon East District Anti-Triad Squad is following up on the incident.