A 16-year-old boy was sexually assaulted on board a train travelling through Colchester, police say.

A man, who got on the train at Colchester Town station, sat next to the boy and spoke to him at around 2pm on October 6.

A British Transport Police spokesman said during the conversation the man took hold of the victim’s arm and forced him to touch the suspect over his clothing in an inappropriate manner.

Now officers are urging witnesses to come forward and have issued a description of a suspect.

PC Steven Smith said: “I am keen to speak to anyone who may have been travelling on the train and might have witnessed the incident. This was a very distressing incident for the victim.

“Everyone has the right to travel on the rail network without fear or intimidation and an investigation is underway to identify this offender and bring him to justice.”

The man is described as white and slightly tanned with short brown hair and stubbly facial hair.

He spoke with a local accent and was wearing a black polo type shirt with a white square outline with a motif of a coffee bean.

He was pushing a blue/turquoise racing type bike with a metal basket on the front.

Call 0800 40 50 40 or text 61016 citing reference 89 of December 28 with information.