Auckland police are promising to follow up on reports of a large number of motorcyclists who took to Auckland's roads on Waitangi Day on dirt bikes.
Videos posted online show riders without helmets doing wheelies and blocking motorways.
Police said many of the bikes were not designed to be ridden on sealed roads.
The riders showed a blatant disregard for other road users and for their own safety, police said.
Anyone with information that can help to identify those involved is asked to contact police.
