Perth Detectives are continuing their investigation into a serious assault in Northbridge on Sunday (January 27) that left one man unconscious.
About 1.30am, two men (both aged 22) left a nearby venue and were walking along James Street Mall when they were approached by a group of people.
The group surrounded the men and the victims were assaulted.
During the assault, one of the victims fell to the ground, leaving him unconscious for several minutes.
The victim was taken to Royal Perth Hospital for treatment.
The other victim received minor injuries.
Detectives have released CCTV images of two men who they believe may be able to assist with their investigation.
The first man was younger than 20 with a medium build and moustache. He was wearing a red cap, dark hooded top (with yellow writing on the front) and long dark pants.
The second man was younger than 20, with a thin build and a moustache. He was wearing a red cap, black t-shirt and long dark pants.
Anyone with any information should call Crime Stoppers on 1800 333 000 or make a report online.