A policeman was assaulted after he was called to a fight in Cheltenham.
Gloucestershire Police received reports of an altercation outside a pizza takeaway in the town's High Street shortly after 0330 BST on Tuesday.
A force spokesman said the officer received a blow to the head and needed hospital treatment.
A 21-year-old local man also sustained minor injuries. A 22-year-old man from Cirencester was arrested on suspicion of assaulting a police officer.
He has been released on police bail pending further inquiries.
The force spokesman appealed for witnesses to come forward.