CCTV footage captures bikies battling with security workers in South Morang shopping centre

Up to five members from the Hells Angels Nomads are seen confronting two known security guards in front of young children and stunned shoppers.

Police said chairs and bottles were thrown during the attack at the busy South Morang shopping centre on Sunday afternoon.

CCTV footage shows a burly man in a white jumper, a security industry worker, land a flurry of punches against the gang.

Another man in a red top is seen smashing another of the group with a bottle.

One man was seen wearing a Hells Angels Nomads T-shirt, he is floored with a vicious blow by the man in the white jumper.

Detective Sen-Constable Matthew McKenzie said the two groups were known to each other but police believe it was a chance encounter.

"We don't think it is any sort of criminal retribution but it may have been a personal dispute that resulted in the altercation between the two groups.

"It is always a risk that when they are known to each other and clash in a public place that they may seek each other out again."

He said the pair exchanged words before the two-minute brawl but police were still investigating how the fight started.

Detective Sen-Constable McKenzie said 100 people would have witnessed the "disgusting and violent confrontation" and were appealing for witnesses to come forward.

Detective Sen-Constable McKenzie said police had spoken to one person involved in the fight but he had refused to give a statement.

Police's bikie-busting Echo Taskforce is assisting local detectives with the investigation.