Firefighters are still battling a scrub fire south of Dargaville.

Heavy machinery and helicopters have been used against the blaze this morning, on conservation land off Te Maire Beach Road.

Fire communications shift manager Scott Osmond says it hasn't spread any larger than around nine hectares.

"Ground crews are still working for the rest of today and will be onsite tomorrow as well.

"Fire is contained."

Osmond says they've been using heavy machinery to contain the fire.

"Working on hotspots, they'll be there till about 6 o'clock tonight.

"It hasn't spread from the initial 8-10 hectares."