A teenager was attacked by a group of men on a train after he asked them to stop singing "sectarian" songs.

The 16-year-old boy sustained cuts to his head and face after being assaulted by four men, two of whom are understood to be wearing Celtic tops, on a Glasgow Central to Kilmarnock train on Saturday.

British Transport Police said it appeared "words were exchanged after the victim asked a group of four men to stop singing songs of a sectarian nature" at around 4.40pm.

The teenager was punched on the head and body during the attack, before a bottle was thrown and smashed in the carriage. He was taken to Royal Alexandra Hospital in Paisley for treatment after the incident.

Officers are reviewing CCTV footage from the train as they try to identify those involved.

Detective Constable Raymond Grimley said: "This was a violent and unsavoury incident leaving other passengers on the train shocked.

"Although we have very clear CCTV footage of those involved, I am urging anyone who was on the train or at the station and has knowledge of the identity of those suspected of the assault to contact the British Transport Police as a matter of urgency."

When the train reached Barrhead, the four attackers left the station in the direction of Carlibar Road.

The group of men are all described as being aged in their mid-20s. One was wearing a grey striped football top with green sleeves while a second man was around 6ft with blond hair.

Another of those involved had short brown hair and was about 5ft 8in, of heavy build and was wearing a green and white football top, black tracksuit trousers and training shoes. A fourth man is described as being about 5ft 11in, of thin build, with short brown hair and was wearing a black jacket and navy trousers.

The incident happened while Celtic were playing Dundee United at Parkhead, which kicked off at 3pm on Saturday.

If you have any information regarding the incident, contact British Transport Police on 0800 405040.