Police are trying to discover the identity of a man who has been found injured in Bradford.
The man was found unconscious by a member of the public in an alleyway at the rear of St Margaret's Road in the Horton Grange area at 1830 BST on Saturday.
He was taken to Bradford Royal Infirmary but later transferred to Leeds General Infirmary where he is being treated for serious head injuries.
Police say the man is about 25-30 years old and was wearing a blue and white shirt and blue tracksuit bottoms.