A GROUP of thugs who sang vile chants about rape before one man exposed himself to passengers were being hunted by police today.

The shocking incident happened on the 5.53 service from Derby to Reading and other passengers were stunned at the gang's rowdy behaviour.

They sang explicit chants about someone being raped before one man dropped his trousers and exposed his privates.

Passengers took to social media to alert British Transport Police (BTP) on January 21.

Officers met the train at Reading Station to intercept the rowdy crowd, but they were unable to track them down.

A spokesman for BTP said: "Police are investigating after a group of men chanted offensive songs and exposed themselves while on board a train to Reading on Saturday (21 January).

"Passengers on the 5.53pm CrossCountry Derby to Reading train texted and tweeted BTP to report the group were singing sexually explicit songs, including one about rape, and that one of the men in the group then indecently exposed himself.

"The incident is understood to have taken place in coach B as the train travelled between Birmingham and Oxford."

The man who exposed himself was described as wearing a Lacoste jumper with a checked shirt.

Anyone with information should contact BTP immediately.

Police Constable Glen Petre, added: “Passengers were quite rightly appalled by what they saw and heard on the train. This kind of disgusting behaviour is totally unacceptable and we are determined to make sure this group account for their actions.

“We are trawling CCTV at the station to try and identify them, but we could do with hearing from anyone else who was on the train and saw what happened, and I would urge any other witnesses to come forward.”