Police are appealing for witnesses to an alleged assault in a club in Chesterfield.
Officers believe that two groups of people were involved in a confrontation in Moo Bar in the early hours of Sunday.
A 21-year-old man from Mansfield suffered a fractured jaw and has undergone surgery at Chesterfield Royal Hospital.
Officers would like to speak to anyone who was in Moo Bar at the time or who has information about the incident.
Anyone who can help with the investigation should contact police on 101 or call Crimestoppers on 0800 555 111 quoting crime number 30421/14.