A man was sexually assaulted by another man after he became separated from his friends on board a train, police have said.
The incident happened after the victim boarded the 11.45pm Glasgow Central to Largs service at the rear carriage on Friday July 2.
He became separated from his friends and asked another man if he had seen them.
The victim was then sexually assaulted by the man, who is described as white, aged in his early 20s, of medium build and around 5ft 9in.
He has blonde curly hair and a nose ring and was wearing dark jeans and trainers.
British Transport Police are investigating the incident and urged anyone with information to contact them by texting 61016, or calling 0800 40 50 40, quoting reference 10 of July 3.
People can also contact Crimestoppers anonymously on 0800 555 111.