A group of men and women were walking along Bridge Street towards Zinc nightclub. As they passed a group of men an altercation occurred which resulted in a man being punched to the floor.
He suffered serious facial injuries, which required hospital treatment.
They would like to hear from anyone who was in the area at the time of the incident, who may have information to help Thier investigation into the incident.
A 22-year-old man arrested on suspicion of assault has been released under investigation.
If you are able to help, call 101, quoting 5217119207.