Taranaki police have arrested seven teenagers who are believed to have had a role in a series of assaults, thefts and driving offences in Stratford.
The teens, aged between 13 and 17, were travelling in two groups in stolen vehicles on Friday morning before being apprehended by police.
In a statement, South Taranaki Response manager Acting Senior Sergeant Andrew Russ said an off-duty police officer spotted a stolen Toyota heading south from New Plymouth on Friday morning and reported it.
A police car then spotted the vehicle at about 7am but the driver tried to ram the patrol car.
Police did not pursue the Toyota but put cordons in place and road spikes nearby, Russ said.
While police were organising the road spikes, a Mazda began fleeing from police and it was discovered it had been in convoy with the initial Toyota, he said.
Police opted to put wider cordons in place but did not pursue the Mazda either, he said.
A short time later police received a report of a car being dumped in Eltham and three people running from the vehicle, who were located and arrested, he said.
About 8am police spotted the Toyota in Stratford, two youths got out of the vehicle and were arrested, while the two still in the car drove out of Stratford and the vehicle was spiked near Cardiff, Russ said.
They kept driving until the wheels disintegrated and then abandoned the car and fled on foot across farmland before also being arrested.
All seven teenagers have been referred to youth services.
Russ said it was believed they had been involved in similar offending over the past few months.
"While resolutions like this are positive, we know they are cold comfort to the people who have been targeted and have lost their vehicles or property or have been assaulted."
Stolen vehicles are often used for joyriding which raises concerns for the safety of the drivers, their passengers and the public, he said.
Police are urging vehicle owners to take measures to make them less attractive to thieves such as ensuring it is locked, parking in a secure spot where possible and considering a vehicle alarm or steering lock.
Police also warned people not to leave valuable items in their vehicles.