A fire investigation is underway at Otumoetai Primary School, after decking and terraces were set alight.

Senior station officer Phil Price says the blaze was contained before it reached classrooms. It appears the fire started in a rubbish bin. It is unknown whether the fire was started accidentally or is more suspicious. The alarm was raised by a passerby.

Firefighters at Otumoetai Primary School this afternoon. Photos: Tracy Hardy.

Firefighters cut away some of the decking to ensure there was no fire under the building and checked for heat sources with thermal imaging equipment. They are dampening down and checking the scene for any potential hot spots.

It is thought the classrooms are not damaged although there was a reasonable amount of smoke.