Hundreds of boyracers caused chaos across Christchurch overnight, drag-racing and doing burnouts while aggressively taunting police in a cat-and-mouse game that used secret social media groups.
Police reportedly struggled to handle the scale of the covertly organised event, named 'Aves Invasion Weekend 2.0'.
While Friday night was played down by police, hundreds of boyracers and associates used Snapchat to communicate hushed-up meeting points across the city last night.
Various meeting spots, including Kaiapoi, Belfast, and the central city around Deans Ave, saw the car enthusiasts in souped-up vehicles descend to perform burnouts, drag-race, and let off fireworks.
Many videos have been posted on social media with number plates blocked out.
They show diesel being poured on public roads for cars to rev their engines and skid, while being cheered on by huge crowds of young people.
Police officers who arrived to break up the party were met with abuse and aggressive behaviour.
Tweeter Paul Le Comte posted that when more than 10 police cars showed up at one point, "all the boy racers started revving their cars and chased them".
"Deans Ave & Moorhouse Ave is blocked off, so they're screaming all directions. Nuts."
They were still cruising and keeping residents awake after sunrise this morning.
The organiser of the event posted on Facebook this morning boasting of its success, even that police in riot gear couldn't stop them.
"We had our ups and downs this weekend. Friday night cops where [sic] rolling our meets. Then Saturday we where [sic] step ahead of the police," They wrote.
"We truely [sic] love seeing the whole chch car scene together and seeing smiles. Can't believe how last night went, it was off the hook. Riot squads couldn't even shut down our meets."
This morning, Canterbury Metro Commander Superintendent Lane Todd issued a statement condemning the boyracers.
While in the past, some boyracer groups have engaged with police over meet-ups, Todd said that relationship appears to have deteriorated.
"Some of the racing enthusiasts who were involved last night, showed some very anti-social behaviour, which wasted extensive police hours, hours which could be spent elsewhere on solving crime," he said.
"Police are very disappointed with their actions and the fact that they are showing total disregard to the safety and peace of our communities.
"When police are responding with time-wasting car enthusiasts, genuine calls for service get less attention and can be potentially missed if police are tied up with unnecessary and thoughtless boy-racer behaviour."
Police are now investigating whether some call-outs last night were hoaxes. Todd warned that police will be looking to prosecute anyone who makes a false complaint to them.
Police reminded drivers that if they break the law, they face fines or even their car being impounded.