Six people have been arrested after a street racing meet in Wairarapa turned violent overnight with a group hurling bottles, rocks and fireworks at police officers.
Police say they broke up the planned activity by what they call anti-social road users on Waingawa Road near Masterton just after 1am.
Officers were confronted by an aggressive group who threw things at them and smashed the back window of a police car.
Police say they arrested six people who face a range of charges.
They also issued multiple infringement notices, suspended some drivers, and impounded two cars.
Masterton mayor Gary Caffell hoped it was a one-off, and told RNZ it was disappointing.
"We pride ourselves on the fact that we welcome people into Masterton. ... We're a very friendly town and this sort of behaviour, it just ... it really guts you when you hear about it."
Caffell said police officers were just trying to do their jobs and uphold the law, and should not be subjected to that kind of behaviour.