An 18-year-old man suffered a broken wrist and fractured eye socket after he was assaulted in a bar in Northampton town centre.
The teenager was grabbed by the throat and pushed to the floor in Balloon Bar in Angel Street, Northampton, at about 2am on Sunday, 11 January.
The victim was then helped up by the same person who had pushed him, who proceeded to throw him out of the fire exit on to Angel Street.
He was then assaulted by three men and suffered a broken wrist and possibly a broken eye socket as a result.
Witnesses or anyone with information are asked to contact Northamptonshire Police on 101. Alternatively, information can be given anonymously to Crimestoppers on 0800 555 111.