Six teenage boys have been arrested after two women were sexually assaulted on a train travelling from Cambridge rail station.
The women, aged 17 and 20-years-old, were waiting at the station when a group of teenage boys approached them.
They all boarded a Kings Lynn-bound train and, during the journey, some of the youths began to touch the women inappropriately and make vulgar comments towards them.
The women left the service as it arrived into Waterbeach station, but the boys stayed on.
Police were alerted and traced some of the group to Ely station, where six were arrested. One boy was arrested on suspicion of sexual assault and the others on public order offences. They were later bailed pending further enquiries.
Investigators still believe two boys are outstanding, and are keen to hear from anyone who may have been on the 9.05pm service from Cambridge on Sunday.
British Transport Police (BTP) is appealing for information after the incident which took place at about around 9.10pm.
Det Con Dave Rabbitt, the investigating officer, said: “This must have been a frightening experience for the two women. It was purely unwanted attention from a group of boys who targeted the pair for whatever reason we are unsure.”
“We will be looking at CCTV from the train, station and surrounding area to gather a full picture of exactly what took place, but I would urge anyone who has any information, no matter how small they may think it is, to contact detectives urgently.”
The arrested boys were aged 13, 14, 14, 15, 15 and 17 years old. They have been bailed to return to police custody on January 4, 2014.
Anyone with information is asked to contact BTP on 0800 40 50 40 quoting background reference LNA/B7 of 27/11/2013. Information can also be passed to the independent charity Crimestoppers, anonymously, on 0800 555 111.
It was previously reported by BTP that all six boys were arrested on suspicion of sexual assault which was incorrect.