A vicious brawl between two underground commuters was caught on camera after a disagreement escalated into violence on a busy train.
The argument erupted in Beijing, China, on the Yizhuang Line of the city's underground.
Mobile phone footage taken by another commuter captured the fight between the two men, one wearing a mask and glasses.
It is not clear what the pair were arguing about but the violence starts when one of them attempts to strike the other with a backhand.
The other man retaliates by punching him in the head and face.