A toilet block has been destroyed and three classrooms damaged in a suspicious fire at Kerikeri High School.
The alarm was raised at 2.20pm today with station officer Andy Hamberger saying flames were shooting out both toilet doors and the rear windows when the brigade arrived.
Volunteer firefighters in breathing apparatus brought the blaze under control and stopped it engulfing the classrooms on either side of the toilets.
Hamberger said the classrooms had sustained water and smoke damage, and the flames had started spreading to another classroom block across a walkway behind the toilets.
''At this stage it looks like it's been purposely lit,'' he said.
No one was injured.
Two appliances and a tanker from Kerikeri Fire Brigade responded, along with police officers and specialist fire investigators from Fire and Emergency NZ.
The school will close on Thursday, on advice from the Ministry of Education, with a thorough damage assessment due to take place in the morning.
In a message to parents principal Elizabeth Forgie said she hoped the school would reopen to senior students, in Years 11-13, on Friday.
She thanked the ''amazing'' fire brigade for their rapid response and making sure the damage was not greater. She was also grateful to fire investigators and the police.
''The students and our staff coped extremely well and followed our evacuation procedures,'' she said.
The last fire at Kerikeri High School was on Queen's Birthday weekend in 2010 when the science block was gutted in an early-morning arson attack.
A teenage girl was arrested in relation to that fire.