Yobs pelted objects at three men in an attack which damaged a tram so badly it was forced out of service.

A group of youths, thought to be in their late teens or early 20s, attacked the men as they left a tram at Woodside stop shortly before 6pm on Thursday (April 25.)

They smashed at least four windows, forcing the tram out of action.

British Transport Police (BTP), who visited the scene the next day to reassure passengers, have appealed for witnesses.

Detective inspector Ash Cooper said: "It’s very early stages at the moment, but we are taking this assault very seriously.

"At the moment it’s not clear why this attack took place, but officers are currently reviewing all available evidence and speaking to witnesses to establish the circumstances.

"This must have been a frightening and upsetting experience for everyone on board at the time, and we will do everything in our power to identify those responsible.

"We would ask anyone who saw the incident take place to contact police immediately."

Anyone with information is asked to contact BTP on 0800 40 50 40 quoting reference B12/LSA of 25/04/2013 or call Crimestoppers anonymously on 0800 555 111.