Police have appealed for witnesses to an assault aboard a train after the Notting Hill Carnival.
In a video posted to Facebook, a woman can be seen inside a carriage claiming a sandwich has been thrown at her before assaulting another woman by grabbing her hair and repeatedly punching her in the face.
The row on the service between London and Birmingham escalates when the victim, wearing a pineapple-themed outfit, asks the woman: “Are you going to slap me into next week?”
“You think I’m going to jail for you?” replies the attacker.
The argument continues before the woman warns, ”Don’t let me take off my wig”, and shortly afterwards attacks her now-seated victim, having removed the wig.
She is seen to grab the victim’s hair and launch a flurry of punches, before dragging the woman into the aisle and kicking her in the head.
A man who appears to be travelling with the victim motions to intervene in the brawl, but another man stops him and an altercation between the pair ensues.
Two other passengers are seen leaving the carriage. The male attacker then jumps over to the female victim and begins to punch her.
Another man subsequently intervenes, and succeeds in ending the brawl.
Towards the end of the clip the female victim can be heard asking, "Why? Why? What have I actually done to you?"
A British Transport Police spokesman said: “We are aware of footage circulating on social media showing an assault on board a Chiltern Train.
“We believe it relates to an incident which took place on a train between London and Birmingham Snow Hill at 9.50pm on 27 August.
“An investigation into this incident is underway, no arrests have been made at this time."
Anyone with information is asked to contact British Transport Police by calling 0800 40 50 40 or texting 61016.
