A MAN is in an induced coma after he was punched in the head while travelling on the Armadale train line in the early hours of Sunday morning (January 21).
Kensington Detectives are investigating the assault which took place about 6.30am.
The 19-year-old victim and his friends were on the Armadale bound train, which they caught from Perth train station on Wellington Street.
During the journey, between Cannington and Beckenham stations, the man and his friends became involved in an altercation with another group on the train.
The victim received a punch to the right side of his head during the altercation, before a friend intervened and helped him to a seat.
The group who were involved in the assault got off at the Beckenham train station.
The victim and his friends stayed on the train until Maddington train station.
The victim became unsteady from the punch and had to be helped by his friend to a seat on the platform.
He was in considerable pain and was taken by ambulance to Royal Perth Hospital where emergency surgery was performed to repair a life threatening brain injury.
The victim was placed in an induced coma.
The offender was described as 18 to 20 years old, dark skinned, approximately 187cms tall, with a slim build and brown hair.
He was wearing a checkered yellow shirt.
There were several people on the train at the time of the incident and detectives would like to speak to them.
Call Crime Stoppers on 1800 333 000, or report the information online.