An old projectile from a World War Two era artillery has been successfully detonated by the defence force in Paraparaumu.
Police were contacted this morning by a family who had found the historic projectile in Belmont Regional Park during the school holidays.
The kids took it home to their grandparents house, and after googling the item they thought it was safe to keep and clean up to take to school for show and tell, the police said in a statement.
Last night the children returned to their home in Paraparaumu with the artillery round in the car.
Another grandparent was concerned about safety and moved the item into the backyard before calling Police this morning.
Police arrived at the house and put a cordon in place, evacuating three nearby houses as a precaution.
The New Zealand Defence Force Bomb Disposal Unit then inspected the projectile, confirming it was potentially still live, deciding it should be detonated in a controlled explosion.
It was then transported to a safe location at Higgins Quarry in Paraparaumu where it was buried and detonated by remote.