A ticket inspector was racially abused on a train between Motherwell and Dalmuir on Saturday.
At around 5.10pm, a passenger was on the 4.15pm service from Motherwell when the ticket inspector asked to see his ticket.
The suspect, who is believed to have been a teenager, then became racially abusive towards him, shouting and swearing.
The offender is described as white, around 5’6” and was wearing a black top with a navy backpack. He was believed to be a teenager.
Anyone with information should call British Transport Police on 0800 40 50 40 or text 61016.