British Transport Police are investigating an assault on-board a northbound London Overground service have released CCTV images in connection.
In a statement, British Transport Police said: “Just before midnight on 10 July, a group of young men were vaping on the service when they were challenged by a member of the public.
“Two of the men then punched the member of public before a second group of young men boarded the train and a melee ensued between the groups.
“At the time of the incident the service was at Harrow and Wealdstone station.
“Officers believe the man in the CCTV images may have information which could help their investigation.”
If you recognise him, or have any information, please contact BTP by texting 61016 or calling 0800 40 50 40 quoting reference 637 of 10 July.
Alternatively, call Crimestoppers anonymously on 0800 555 111.