Shocking footage has emerged showing the moment a violent brawl broke out on a busy train in Perth.
The fight was captured on a Fremantle train on Saturday night by another passenger.
Witnesses claim the brawl was sparked after the man in darker clothing attacked a stranger for no reason.
The man in the grey shirt then approached the man before punching him.
The pair began fighting in front of the shocked commuters before a citizen’s arrest was performed.
It is understood the instigator was held under citizen’s arrest until officers arrived.
