Police are appealing for information after a teenager was sexually assaulted on a train.

The incident occurred after the victim, aged 16, boarded the Northern Service to York at Preston at around 7.50pm on June 18.

After she took a seat, a man sat down next to her and began engaging her in conversation before touching her inappropriately.

He left the train at Blackburn.

DC Chris Biggs, investigating, said: “As part of our enquiries we’d like to hear from anyone who may have been on the same service and who may have witnessed what happened.

“We do not tolerate any form of unwanted sexual behaviour and we are working to identify and trace the offender. The victim was understandably left distressed and shaken by what happened.

More: Preston Station revamp is now finished

“We are today releasing a CCTV image of a man we would like to speak with in connection with our enquiries. If you know who this man is then please get in touch as soon as possible.

“Your information could prove vital in our enquiries.”

Anyone with any information is asked to contact BTP by sending a text to 61016 or by calling 0800 40 50 40 quoting reference 105 of 12/07/2017.

Alternatively, call Crimestoppers anonymously on 0800 555 111.