Efforts to extinguish a large fire burning for the past eight days west of Dargaville are continuing.
Thick smoke has prompted some residents to leave their homes while Te Whatu Ora has issued a health warning advising people to keep their windows closed and limit outdoor exercise.
The blaze started on 1 February on farmland at Scottys Camp Rd, near the coastal settlement of Baylys Beach, and spread through 15ha of wetland vegetation in the first night.
The fire has since been contained with more than 30 firefighters hoping to make progress today in curtailing the smoke.
Fire and Emergency New Zealand (FENZ) assistant commander Denis Cooper said the blaze had spread into underground stumps and logs, making it hard to extinguish.
A bulldozer and a digger were also being used as firefighters tried to reach deep-seated hotspots.
Dargaville firefighters reported the blaze started when a water pump caught fire, but FENZ is carrying out an investigation.
Te Whatu Ora urged nearby residents to call Healthline on 0800 611 116 if they had any health concerns or breathing difficulties as a result of the smoke.
The Baylys Beach blaze is the first major, multi-day fire of the season in Northland.
Despite predictions of a dry summer and possibly even drought, regular rainfall has so far kept the fire risk to a manageable level.
Most of Northland remains in an open fire season, except for the fire-prone top of the Far North - the area north of Kaitāia-Awaroa Road and State Highway 10 - where a total fire ban is in force.