Christchurch police are alarmed that children as young as eight are behind a surge of car thefts around the city over the past few months.
A spike in car thefts, primarily committed by young people aged 11 to 14, has been reported - with the ensuing getaways often resulting in serious crashes.
Police are now fearful that the upturn of thefts, and the "dangerous" nature of them, will result in someone being killed after several "close calls".
Superintendent Lane Todd told Checkpoint a total of 59 cars were stolen over one weekend earlier this month.
The swell of offending during the two-day stretch was kindled after two groups, coordinating via social media, competed to see who could steal the most cars over a 48-hour period.
The youngsters, who were aged between 12 and 14, were later arrested.
Another string of alleged break-ins during a weekday morning last week required a police helicopter to be deployed, leading to arrests.
Because they were being carried out near schools and during drop-off hours, police deemed the risk too high to pursue on the ground.
Over the past three to four months there had been a "huge increase of youth offending in relation to stealing cars and to a lesser degree with ram raids".
"Their driving behaviour is quite dangerous. They are actively ramming innocent vehicles, and in some cases, ramming police vehicles. And they're also putting themselves at risk, but also the wider community."
He said it was a "significant concern for police".
"My personal biggest fear is that they're going to be involved in a fatal crash and an innocent party will be killed.
"We've had some close calls in relation to some serious crashes, but we've had no one killed yet. But that's my biggest fear."
Toyota Aquas and Mazda Demios have been the cars of choice.
"They crash the vehicles and then they'll go steal other cars," Todd said.
Over the past two years, police had recorded 447 car thefts committed by youths between the ages of 10 and 17 in the Christchurch metropolitan area.
He said this made up 7.5 percent of thefts committed nationally.
Police had noted thefts had at least doubled during the weekends over the past six months in Christchurch,
"Whilst on average it might've been 10 to 20, now we're talking more 30 to 40," Todd said.
To combat youth offending, police had ramped up staffing in teams which focused on "high-end youth offenders".
Police were also trialling a programme called Fast Track in Christchurch, which was piloted in parts of Auckland last year, and sees police partnering with Oranga Tamariki and other agencies.
It focuses on young people aged between 10 and 13 who are involved in serious or persistent offending, wrapping support around their families.
"We know it's worked really well in Auckland, so we're hoping it will replicate down here in Christchurch."
He said the offenders were getting ideas from social media, where they were also working in teams virtually, without actually meeting people.
Police were also concerned many of the children had not engaged in school or "positive activities" following Covid-19.
Todd said many of the young offenders were savvy enough to know their rights and had a good grasp of legal procedures once arrested.
"Depending on their age, they may or may not end up in youth court. They may not necessarily get held into a secure environment so then they're released back to the family.
"And then they're back out on the streets tonight. That just makes our job that much harder."