A group of young people on motorcycles attacked a cafe in the province of Baccan in northern Vietnam.
The incident was recorded by surveillance cameras, and the footage was released on YouTube.
The video shows how the restaurant's visitors scattered in all directions when they spotted the raiders.
The attackers destroyed furniture, and set some items on fire, but the staff managed to repel the attack.
According to the video's caption, there were about 30 attackers armed with knives, clubs and scraps of metal pipes. Another camera captured explosions, presumably of gas bombs.
The raiders fled the scene, and the police launched an inquiry into the incident.