A man is in hospital after being hit with a metal pole on a Northbridge street last night in a possible vigilante attack.
Police responded to a report of two men fighting on the street about 11pm, Sgt Gerry Cassidy said.
The attacker told police he had disturbed the other man trying to break into a house on Monger Street and they became involved in a fight.
The alleged robber sustained injuries including a fractured spine, ribs and finger and bruising and swelling to his face.
He is in hospital with serious injuries and has yet to give his side of the incident to police, Sgt Cassidy said.
The other man told police he acted in self defence.
Investigations are continuing.
Any witnesses are asked to contact Crime Stoppers on 1800 333 000.