A fire that ravaged a scrap metal yard in Papakura earlier today is finally dying down.
A health warning sent to nearby residents earlier in the day warning them to close all windows and doors, put air-conditioning on to re-circulate and to call Healthline if they feel unwell has been lifted, Fire and Emergency NZ (Fenz) said.
In an update at 5.30pm, Fenz said 12 fire appliances were still in attendance damping down hotspots.
"Excavators [are] working to turn over the debris [and] continuing to work with water to dampen down hotspots.
"We've cancelled the emergency mobile alert. The smoke has dissipated considerably."
The blaze sent black plumes of smoke into the sky when it was at its height. A reporter at the scene said people who were still in the area were now wearing masks.
Anyone heading home that way had been advised to make other plans.
Earlier in the day, Counties Manukau Fire area commander Geoff Purcell explained the fire was about 20m deep and the only way to tackle it was to hose it down, tear parts of it away with an excavator and putting out the flames - before repeating the process.
"It's going to take quite a few hours to get on top of this and people that drive through this area on their way home - at 5 o'clock- I'd suggest they start planning an alternative route," he said.
"We anticipate to be going through into the evening before this fire is extinguished.
"That smoke nuisance is going to continue late into the night."
Up to 10 fire appliances and two helicopters have been at the site on Hunua Rd since just after 8am, when the alarm was first raised about a car on fire.
An update at 10.30am said crews were still working to bring the blaze under control.
"As there are large volumes of smoke in the area, keep doors and windows shut as a precautionary measures," a Fire and Emergency NZ statement said.
Workers from nearby businesses have evacuated the scene.
People have been posting on social media from as far away as Pukekohe saying they can see the smoke from the blaze.
A witness said there was a "definite plastic/chemical smell".
Shortly before 9.30am, police put out a warning to locals.
"Local residents in the Papakura area are being asked to stay indoors due to the large amount of smoke in the area."
Firefighters have come from stations around the South Auckland and city areas, including from Ōtāhuhu, Māngere, Clevedon, Ōtara, Papakura, Papatoetoe, Pukekohe, Avondale, Parnell and Ellerslie.
Fire services were called to the scene on Hunua Rd just after 8am.
A northern fire communications spokeswoman said they got the first report of the blaze at 8.03am.
Fire and Emergency NZ confirmed they are at a scrap metal yard and the size of the blaze is currently measuring about 25m by 15m.
There are no reports of injuries, the spokeswoman said, and there is no danger to any neighbouring properties at this stage.
St John paramedics are there as a precaution, a spokesman said.
"Upon arrival, it was found that the fire had engulfed a large pile of scrap cars and a greater alarm was transmitted to respond more resources."
Motorists in the area are also being encouraged to stay away. Police have closed off a section of Hunua Rd between Settlement Rd and Boundary Rd. Diversions are in place.