Hawera's fire chief said it's too early to say whether a blaze that's gutted part of the local intermediate was arson.

Crews from around Taranaki have spent the morning battling the fire, which took hold before six am.

Michael Fairweather said it's now out and crews are working to make the site safe for investigators.

He said they're are scaling back at the moment.

Mr Fairweather said four fire engines an around 20 fire fighters remain at the scene.

Fire Service central communications shift manager Jan Wills said at least two classrooms in the block of eight were in flames.

She said a dozen fire appliances were called to the scene earlier, and remain on site

The school will be closed for the day.