A 29-year-old man needed hospital treatment for head injuries following an assault in Hartlepool at the weekend.
The man is alleged to have been assaulted by three men at about 4.20am on Saturday, February 1 on Whitby Street.
He suffered cuts, bruising and swelling to his head and was transported to the One Life Centre but was later transferred to the University Hospital of North Tees.
Four men aged 19, 22, 23 and 25 were arrested on suspicion of section 47 actual bodily harm and were bailed pending further inquiries.
Any witnesses to the incident are asked to contact PC Holly Angus on 101 or Crimestoppers anonymously on 0800-555-111.