Detectives are investigating a serious attack in Halifax.
A 46-year-old man suffered face injuries in the assault in Conway Street, off Parkinson Lane, just after 2.45am on Tuesday.
He was taken to Calderdale Royal Hospital where he was treated and discharged.
Detectives want to speak to a man who described as white, in his 20s, 5ft 7ins to 5ft 8ins tall and of medium build, with fair hair.
Anyone who witnessed the attack or who has any information is asked to call Calderdale CID on 0845 6060606, or Crimestoppers, anonymously, on 0800 555111.