Two disused schools in the lower North Island have been badly damaged by fires suspected to have been deliberately lit.
Fire crews have been on watch overnight at the site of a fire that badly damaged the old Petone Technical College in the Hutt Valley on Friday night.
The fire destroyed the upper floor of a former classroom block. A second fire that damaged curtains and a mattress about 100 metres away was started after crews had already arrived to deal with the first blaze.
Meanwhile, the Fire Service says it was called to the disused Muhunoa East School in Ohau, south of Levin, at about 11pm.
The school, which was built in 1904, was well alight. The police and fire safety inspectors will investigate the site on Saturday.
No one was hurt in any of the fires, but the Fire Service's assistant area commander for Hutt-Wairarapa, Bernie Rush, says the Petone block was old and potentially dangerous, and crews had to take special care.
No source of ignition
"The biggest concern to me is injury to our firefighters," Mr Rush says. "There's a big risk to our guys having to deal with a fire like this."
He says the fire was almost certainly deliberately lit, as there was no power connected to the building and no source of ignition.
The building will have to be demolished. The police are to investigate the site on Saturday.
The Petone Tech buildings were being administered by the Office of Treaty Settlements for resolution of a Treaty grievance.
On Thursday night, crews fought two fires - which they believe were deliberately lit - at Wellington's Basin Reserve.
In Christchurch, crews put out a fire at a house and garage on Linwood Avenue at just before 4am.