Angry boy racers have attacked a police car in Christchurch, kicking in the doors and smashing its windows, according to witnesses.
A large crowd gathered for the "Aves Invasion Weekend" promoted on Facebook, with around 1600 people saying they planned on attending.
But the event disintegrated into "anti-social behaviour" on Saturday night as the hoons began doing burnouts and skids on the road.
Police were called after receiving reports of the disturbances but faced an angry group.
"Police were called to a traffic offence incident around 11:15pm on Sawyers Arms Rd where multiple vehicles were blocking access," a spokesperson told Newshub.
"A police patrol vehicle was set upon on arrival. A deterrence operation was undertaken by Police to prevent further anti-social behaviour."
Video from the event, one labelled "FTP", shows a police vehicle "boxed in" by the rowdy crowd. Its doors are kicked and someone jumps on the bonnet while another screams "tip it over!"
Witnesses report the car was left with smashed windows and damaged bodywork.
"We stood our ground and made that pig back the f**k up," one poster said.
Others, however, were less complementary about the boy racers' behaviour, with one labelling it "muppet central".
"The car scene is different for every enthusiast and they are just doing their job you'd want them or an ambulance there pretty quickly if a fight broke out or someone did get hit," one person commented.
"Keep the skids up, but stay safe, and respect those who are just doing their jobs and trying to stop deaths on the roads," another wrote.