An 11-year-old Romford schoolgirl was dragged to the back of a Shenfield to Liverpool Street-bound train and sexually assaulted by a lanky pervert, in a terrifying daytime ordeal.

The youngster, on her way home from school, boarded the train at Chadwell Heath Station at around 3.40pm last Thursday.

She sat down on the “typically busy” service, and was shortly after approached by a man who took a seat next to her and began talking to her.

He then pulled the schoolgirl into the back carriage of the train where he touched her indecently.

The victim, from Plaistow, east London, fled at Maryland Station and police were called.

The man alighted at the same stop but had escaped by the time police arrived.

Detective Constable Sally Everritt, investigating officer from British Transport Police (BTP), said: “Both the victim and the man were initially sat in one of the rear coaches of what is typically a busy service. I want to speak to anyone who was travelling on this train and who saw either the victim or the man we are trying to identify.”

The man is described as black, of thin build, aged 25-30 years and 6’2” tall.

He had a small moustache and beard and was wearing a red t-shirt, red baseball cap, and a dark body warmer with red lining.

The victim, who is white, was wearing a white polo-shirt, black leather jacket, black trousers and white trainers.

DC Everritt added: “Offences like this are very rare on the rail network in east London but we are treating this incident very seriously and are currently conducting several lines of enquiry to trace the man responsible. We will also be speaking with witnesses and carrying out anniversary visits in the area.”

Anyone with information is asked to contact BTP on 0800 40 50 40, quoting reference B5/LNA of 24/05/2011, or Crimestoppers anonymously on 0800 555 111.