A GANG punched a teenager to the floor of a train before chasing him onto a station platform and continuing their attack.
The 19 year-old victim was left bloodied and bruised by three men and a woman on a train travelling from Fife to Edinburgh last month.
The running battle ended at the capital’s Haymarket station, where the gang eventually left the teenager.
Police said they want to speak to passengers on the 23.23 Cardenden to Waverley service on 21 June who may have witnessed the attack.
British Transport Police detective constable David McAllister said: “The victim was onboard the service when he was approached by a group of three men and one woman.
“They began to shout abuse at the victim, before pushing him to the ground and repeatedly punching him in the face.
“As the victim left the service at Haymarket station, the group followed him where they continued to assault him.
“We have spoken to witnesses at the scene and have obtained detailed descriptions of those believed to be involved, which we hope will help the public in bringing vital information to the investigation.
“We are continuing to make local enquiries into the incident and are also asking anyone who has any information to get in touch.”
Anyone with any information which can assist officers with their enquiries is asked to contact British Transport Police on 0800 40 50 40, quoting incident number 50 of 22/06/2010, or Crimestoppers anonymously on 0800 555 111.