A man harassed two teenage girls before sexually assaulting a woman on board a train in Glasgow.
The incident took place on the train between Dalmuir and Larkhall at around 11.30pm on Monday, July 19.
The man, described as having a long grey beard, approached the 14-year-olds after boarding at Argyle Street station in the city centre.
The teens were forced to tell him to leave them alone, but as he left the train he groped another woman who was standing nearby.
He then got off the train at Larkhall just before midnight.
Police are appealing for witnesses as they look to trace the man, described as being white, bald and in his late fifties or early sixties.
At the time of the incident he had a long grey beard and was wearing a green khaki t-shirt, blue jeans and black sunglasses.
Officers are keen to speak to anyone on-board the service who may have witnessed the incident to help their investigation.
Witnesses or anyone with information can contact BTP by texting 61016 or calling 0800 40 50 40.