A man was left unconscious after he was attacked in Oxford city centre.

Police officers were called to Cornmarket – outside the Vodafone shop – at 1.15am today after the man in his 20s was punched and knocked unconscious.

The attack is believed to have been unprovoked, Thames Valley Police has said.

The offender is described as white, 5ft 6ins, with short brown hair and of muscular build.

He was wearing a green T-shirt and tan-coloured trousers.

A 37-year-old man from Oxford has been arrested in connection with the incident on suspicion of affray and has been bailed until Friday, September 26.