The assaults were reported to have happened outside the entrance to the Drift Bar on Thursday night, just before 23:50.
The alleged victims’ injuries are unknown but are not believed to be serious, the Force said.
The suspect is described as white, five feet nine inches tall and of stocky build. He was wearing dark trousers, a white t-shirt and a dark jacket, which he removed after the assaults.
Anyone who saw the incidents – including motorists who were driving by – are being urged to contact police on 612612.
They can also contact Crimestoppers anonymously on 0800 555 111 or via their online form.