A man is in hospital with burns following a suspicious fire on Auckland's North Shore.
Emergency services were called to the Inga Road home in Milford at 5.40pm after smoke was seen coming from a garage.
One man who was driving along Beach Road told the Herald the ground shook and he heard an explosion.
Police said a man was seen moving pots and pans in an agitated state.
He was allegedly aggressive towards emergency services and tried to run away but was chased by police and arrested.
Police and a member of the public who tried to help put the fire out have had to be decontaminated using a specialist Fire Service decontamination unit.