Today's huge blaze the third fire at same Auckland scrap metal yard in 10 months

A massive blaze still burning at a scrap metal yard in Auckland is the third fire at the site in the last 10 months.

Fire crews were called to the blaze at Sims Pacific Metals recycling yard on James Fletcher Drive in Otahuhu, at 1.55am today and it's likely to continue burning until well into tomorrow.

It has taken 80 firefighters and 21 trucks to battle the fire which sparked explosions at the yard, shut down nearby roads and schools and produced thick columns of smoke, visible across the city.

Sixty firefighters attended a blaze last May which gutted the factory.

And in 2007, four people were hospitalised in another fire after what's thought were exploding aerosol cans in the scrap metal shredding plant.

Firefighters struggled to contain the out of control blaze this morning.

"The priority on this job was to get a lot of water on the fire as quick as possible. So we've had to bring in additional water from some distance. We're using aerial appliances and ground monitors to control the fire," said Barry Fox, Auckland Assist Area Commander.

The fire broke out at a scrap recycling plant in a pile of car pieces, and can be seen from nearby One Tree Hill. Source: 1 NEWS

There have been no reports of any injuries at the site.

The fire is in a 1600-tonne pile of scrap metal, including old cars and tyres and  crews have been using excavators to try break apart the pile.

"The pile's about 110m by 80m across, and 15 metres deep. So the fire's very deep-seated, and it's taking a lot of work by our crews to extinguish that," said Geoff Purcell of Fire and Emergency NZ.

While the cause of this fire is not yet known, authorities are aware of potential hazards.

Auckland City Assistant Area Commander Barry Fox said the fire was 100m by 70m in area and as high as 12m in some places. Source: 1 NEWS

"The cars before they're shredded, they're drained of fuels and oils. But there are still some minor explosions going off, tanks, bits and pieces that are contained within the scrap heap," Mr Fox said.

James Fletcher Drive will remain closed until at least midday tomorrow and fire officials this afternoon said the fire could burn for another 24 hours.

People living in the area are being encouraged to keep out of smoke, stay inside, shut all doors and windows and close down ventilation systems if they can. 

Any smoke residue should be wet wiped from hard surfaces, especially areas where food is prepared, floors and window sills.

King's College in Otahuhu closed early because of smoke from the fire travelling across the school grounds.

The college posted on Facebook at about 2pm, saying there is no immediate cause for alarm, but it had chosen this course of action as the health and safety of its students and staff is paramount. 

The college said it anticipates students will be able to return to tomorrow.

Explosions were heard coming from the business in Otahuhu early this morning. Source: 1 NEWS