Police have confirmed that more than 1000 people were a part of illegal street races in Hamilton over several hours early on Sunday morning.
Waikato police said they received reports of a large gathering of cars and people at the intersection of Horotiu Road and Great South Road, about 2.15am on Sunday.
Four police cars were rammed while "hostile individuals" started to throw projectiles, set off fireworks and shine lasers at officers, detective sergeant Matt Lee said.
An 18-year-old Ōtorohanga man has since been charged with intentional damage causing danger to life, dangerous driving and receiving stolen property in relation to one of the ramming incidents were an officer was knocked to the ground and received minor injuries, he said.
He has been bailed and was set to appear in the Hamilton District Court on Friday.
Police have also recovered a freshly painted ute believed to have been involved in the ramming after executing search warrants at two Ōtorohanga properties, and enquiries in Huntly, where the vehicle was found.
A Hamilton City councillor said growing reckless and violent behaviour at illegal street racing events was putting people in danger and disrupting neighbourhoods.
Meanwhile, the minister of transport said new legislation could be on the way to curb gatherings of "increasingly hostile" car enthusiasts.
Officers continued to investigate "unlawful behaviour" from the weekend, Lee said.
"We want to thank the members of the public who have provided valuable information and our warning to all those involved is that we are continuing to review the video evidence recorded by those who took part in this event, and we will be making every effort to hold people to account for their dangerous and violent actions."
Anyone with information that could help the investigation was urged to get in touch with police.