Witnesses who saw a man assault a girl on a train in Sheffield are being urged to come forward.
A group of three girls were travelling between Meadowhall and Sheffield when a man who was sat nearby attempted to steal one of their mobile phones.
He repeatedly pushed one girl's head down as he tried to snatch her phone.
The man eventually stole another girl's phone but she managed to grab it back before he left the train.
PC Mark Mason, of British Transport Police, said: “A group of three 15-year-old girls boarded a train at Meadowhall.
"As the train made its way to Sheffield, a man who was sitting nearby got up from his seat and repeatedly pushed one of the girls' head down and attempted to take her mobile phone.
"He eventually moved on to her friend and snatched her phone which she managed to grab from him before he left the train at Sheffield."
The incident happened on the 4.33pm Northern Rail service from Meadowhall to Sheffield on Friday, July 1.
The culprit was white, in his late twenties or early thirties and had short, black hair.
He was wearing blue jeans and a waterproof jacket at the time.
British Transport Police on 0800 40 50 40 or text 61016 quoting reference number 184 of July 15.