Three youths riding bikes attacked a man in Clifton, York.
The victim, a man in his 30s, was walking his dog when he was assaulted on Crombie Avenue near to Lady Mill Garth in Clifton at 6.30pm last Wednesday (January 11).
The victim sustained head injuries which, fortunately, were not believed to be serious. He did not know his attackers.
The ringleader is described as a white male, 15 to 16 years old, with short dark hair and dark eyebrows.
All three offenders were on bikes and were wearing dark tracksuits.
Anyone who knows the identity of the attackers or has information that could assist the investigation should contact North Yorkshire Police.