Five people have been arrested and a police investigation is under way.
Inspector Adam Pyne said a police operation had been monitoring the movements and behaviour of gang members in Counties Manukau on Wednesday.
"While most were well behaved, police did observe some poor driving behaviour on parts of the route and intervened on several occasions, as the group travelled to West Auckland and returned towards Flat Bush," Inspector Pyne said.
Two arrests were made for driving offences and two motorbikes were seized.
The group of at least 100 were then monitored travelling to a function at a bar at Botany Junction.
At the function, one of the attendees did a burn-out outside the bar.
As police intervened, some of the other attendees became "aggressive" and threw objects at officers, Pyne said.
A staff member from a neighbouring restaurant told RNZ a man on a motorbike was doing burn-outs.
"Police all started chasing him," he said.
He said about "30 cops" were at the scene and said it was a "waste of taxpayers' money".
The man said no one had been injured, but the restaurant had to close and cancel all bookings.
Another person in the area said there were "quite a few police cars" and a police van across the road.
"A lot of police are over there," she said.
Three people were arrested, one for wearing gang insignia in a public place
Police also seized another three motorbikes at the bar.
