A childcare centre and a building on a marae have been evacuated following the discovery of explosive material in a Nelson park. There will be a visible police presence at Founders Heritage Park for the next few hours (file picture). Photo: RNZ / Tracy Neal Members of the public are urged to avoid Founders Heritage Park in Atawhai Drive while the Defence Force's explosive ordnance disposal unit assesses the material. The park's carpark has also been closed as a safety precaution. Police said there would be a visible police presence in the area for the next couple of hours while the unit disposed of the material safely.