A man has been taken to hospital with serious burns after he was apparently set on fire in a nightclub.
The 34-year-old is believed to have been at the bar of the club when he was set alight and suffered serious burns to his hands and torso, Norfolk Police said.
Four men, aged 24, 26, 28 and 33, were arrested after police were called to reports of a disturbance in Long John's Showbar on Britannia Pier in Great Yarmouth at 1.30am.
The injured man was taken to the James Paget University Hospital in the town but was later transferred to Broomfield specialist burns unit in Chelmsford, Essex, where he is in a serious but non life-threatening condition.
The arrested men were released several hours later on bail to return to Great Yarmouth Police Investigation Centre pending further inquiries. Three are to return in late May, while the 28-year-old must answer in early June.
It is understood the five men, from the Sheffield area, are known to one another and the force said they were treating the incident as an isolated case.