A man has been left with serious head injuries after a fight outside a bar in Cleethorpes town centre.
Police were called to the Rift bar on High Street at 2.40am on Thursday 13 April to reports a man had been assaulted.
The 31-year-old was taken to hospital with a serious laceration to his head.
A 30-year-old man has been arrested on suspicion of wounding with intent and assault of an emergency worker.
Detective Inspector Tom Kelly from Humberside Police said: "A scene guard was in place whilst we conduct lines of enquiry to understand the circumstances surrounding the altercation but has since been removed.
"I understand this may cause some concern to residents, please come to talk to us if you have any concerns."
Police are urging anyone who has information to assist them in their investigation to call 101.