Police are hunting for a suspected bikie gang member who punched the side mirror off a vehicle on the Bruce Highway north of Brisbane.

Police say two motorcyclists wearing Rebels outlaw motorcycle gang clothing were travelling north at Caboolture about 4.45pm Sunday when an unspecified "incident" sparked an attack on a motorist's vehicle.

"One of the motorcyclists punched the side mirror off the vehicle before fleeing," Detective Acting Inspector David Somerville said.

"This brazen display of behaviour towards members of the public is definitely concerning."

The incident happened about 4.45pm on Sunday. Police want any witnesses to contact Crime Stoppers on 1800 333 000.

AAP