Nottinghamshire Police have released images of four men they want to speak to after an assault.
A man suffered a head injury and needed stitches after he was punched in the head inside the Saltwater bar, based in the Cornerhouse.
The attack took place at around 11.45pm on March, 3.
The first man is described as mixed race and of a slim build with short dark hair, the second is white with short brown hair and of a slim build, the third is white with short balding hair and of a medium build and the fourth man is white of a medium build with short dark curly hair and a beard.
If you recognise the men in the photos or have any information that could help, contact Nottinghamshire Police on 101 quoting incident 237 of March 4.