According to the Rural Fire Service on Friday morning, the bushfire, burning between Narrabri and Coonabarabran, had swelled to almost 8,000 hectares in size after southerly and hot temperatures on Thursday night.

The fire, which erupted as three separate blazes on Wednesday afternoon from lightning strikes, spread and quickly became two fires, before the fire fronts combined on Thursday night.

Following intense efforts by firefighting crews on the ground as well as a sustained aerial attack, the fire is being brought under control, the RFS confirmed.

The Newell Highway between Narrabri and Coonabarabran has also reopened on Friday with changed traffic conditions.

The highway is open with a reduced speed limit as there is still some smoke in the area affecting visibility, police said.

Both lanes of traffic are reduced to an 80kph limit with motorists urged to exercise caution near the fire zone..

The smoke from the massive bushfire has spread and can be seen from as far away as the Gunnedah and Liverpool Plains areas.

EARLIER: TWO massive water bombing tankers were last night helping to battle two large bushfires burning out of control in the Pilliga Forest.

Southern Belle – the Rural Fire Service’s monster air tanker – along with Thor, a 68-tonne Hercules tanker, were deployed to the fire zone yesterday between Narrabri and Coonabarabran, from the service’s Sydney base to drop tens of thousands of litres of fire retardant.

The fires, which crews believe were sparked by lightning strikes on Wednesday afternoon, merged yesterday and were expected to  create a giant fire last night under forecast southerly conditions.

The fires forced the closure of the Newell Highway, between the Oxley and Kamilaroi highways, after it jumped the road in two locations.

The Dandry area was expected to remain a no-go zone until at least today as dozens of firefighters worked to bring the blaze under control.

RFS media officer, Inspector Graham Brown, told The Leader no properties were under direct threat late yesterday.

“We have had the police door -knock an area called Tannawanda and advised the people there to be prepared, because they are currently getting a lot of smoke,” he said.

More than 40 firefighters from Coonabarabran and Narrabri were working from the ground, backed by National Parks crews, bulldozers, heavy machinery, four water bombers, as well as the two monstrous tankers.

“The crews are out there working fairly hard, and the weather is best described as stifling for the firefighters,” Inspector Brown said.

Southern Belle, which can carry up to 44,000 litres of retardant or water, was fuelled and loaded with retardant at its Richmond base yesterday morning, before it dropped a load on the fire zone, and returned to base.

Thor, a Hercules C-130 tanker, can carry up to 15,480 litres of water or retardant and made several drops on the fire after reloading in Dubbo.

Last night, the fire grounds had swelled to 5500 hectares and were burning on both sides of the Newell Highway.

Fire controllers from the Liverpool Plains, North West and Gwydir were deployed to Coonabarabran yesterday to co-ordinate the firefighting effort, with a control centre set up.

North-westerly winds were pushing the fire south yesterday, but a southerly change forecast last night was expected to change the direction of the fire, and push it together.

Diversions were in place for stranded motorists needing to travel between Coonabarabran and Narrabri, with drivers advised to use the Oxley Highway and Kamilaroi Highway via Gunnedah instead.