Two helicopters and 10 fire appliances are being used to fight a blaze that has engulfed four hectares of pine trees and grass in West Coast Road, Makarau, north of Helensville in Auckland - and forced the evacuation of half a dozen houses.

Fire service spokesman Scott Osmond said they have been fighting the blaze since 10 this morning and it's still not under control.

He said five or six houses downwind of the fire have been evacuated, not so much because of danger from the flames but because of heavy smoke.