Authorities have been going door-to-door in parts of Tennant Creek, warning residents that a major bushfire could spread to the town amid extreme fire conditions.

A section of the massive fire was upgraded to Watch and Act level overnight, as strong winds pushed a “finger” of the fire front 60 kilometres closer to the town over 24 hours.

Firefighters from the NT and South Australia, along with volunteers and farmers, are working together to tackle the blaze.

Deputy Chief Fire Officer Josh Fischer said winds gusting up to 50 kilometres per hour and heavy fuel loads were causing “intense fire behaviour”, with flames reaching heights of more than 15 metres.

He said the fire broke containment lines last night as the rapidly moving blaze and “very difficult conditions” on the ground made it difficult for firefighters and landowners to safely back-burn.

Mr Fischer said the fire could spread “50 kilometres in one night”, and was currently only 60 kilometres from Tennant Creek.

“We’ve got high winds again this morning … so we do expect, based on what we’ve witnessed to date, that that fire does have the high potential to continue to spread,” he said.

He said firefighters believed the blaze was currently burning near the Gosse River area.

“But until we can get aerial observation over the top we won’t exactly know whether the Gosse River has been able to hold it,” Mr Fischer said.

Mr Fischer said  NT Police officers had doorknocked residents on the southern and eastern sides of Tennant Creek on Sunday evening to give them an early warning the fire could impact their properties. 

He said additional resources were being deployed to Tennant Creek, but they might not land until this afternoon, with the fire spreading “faster than forecast”.

Bushfires NT chief fire controller Tony Fuller said the Watch and Act alert would remain in place for now, as heavy smoke continued to spread over Tennant Creek.

He said the Australian Defence Force was also sending assistance, including two bulldozers and a grader to construct firebreaks around Tennant Creek.

Mr Fischer said large fires were not uncommon in the NT, but it was unusual to see a fire of this ferocity at this time of year.

Separate fire sees residents evacuated

Emergency services also responded yesterday to a “fast-moving fire” at Rusty Camp, south-east of Tennant Creek.

Mr Fischer said the fire reached about 100 hectares in size before firefighters could safely contain it.

Nearby residents were evacuated to a shelter at Tennant Creek High School, but were cleared to return to their homes after 5pm.

Authorities are investigating the blaze, but said the area of origin was known, with a camp structure destroyed early in the fire.

Mr Fischer said it was the first time fixed-wing water bombers had been deployed in the Barkly region.

“They certainly assisted the ground crews to get in front of the fire to be able to undertake that defensive back-burning operation,” he said.

“If it weren’t for the water bombers, we may have seen the fire spread further and potentially onto those residential homes adjacent to the fire area.”