A teenager needed hospital treatment after he was hit on the head walking through Bicester.

Police are appealing for help to trace the person who attacked him as he walked near Bicester Library, in Old Place Yard last Saturday (September 8).

The 17-year-old had left a fairground in Pingle Field when he was attacked at about 9.15pm.

The attacker, described as black and aged between 17 and 19, ran up behind the victim and struck him on the head, leaving him almost unconscious. The victim was taken to the John Radcliffe Hospital, Oxford, for treatment.

PC Matt Jenkins described the incident as a "completely unprovoked attack".

He said the attacker was with a group, which included several teenage girls.

"Anyone who saw the incident, should contact police," he said.

PC Jenkins can be contacted on 01869 364520.