Police are questioning a man suspected of arson as Northern Territory firefighters battle the worst of today's catastrophic fire conditions.
Temperatures in the high 30s, low humidity and wind gusts of up to 60 kilometres per hour hindered efforts to contain two out-of-control fires on Thursday.
At 5:30pm, one watch and act warning remained in place for a fire on the outskirts of Litchfield National Park.
The blaze, near Fowler Road in Batchelor, broke through a containment line earlier in the day.
"It's got potential to run through to Rum Jungle estate, so a number of houses out there and businesses as well," Andrew Turner from Bushfires NT said.
"There's a fair amount of concern in regard to that."
A separate fire near Strickland Road, north of Adelaide River, has now been contained after it also broke containment lines earlier, causing the Stuart Highway to briefly close.
Emergency services have been monitoring a further two blazes, including one at Letchford Road and Meade Road in Darwin River.
"And about 10 kilometres south of Adelaide River [there's] another fire that we haven't got the resources to attend, so we're still investigating that," Mr Turner said.
Superintendent Daniel Shean confirmed a man is under investigation in relation to the Strickland Road blaze.
Authorities are also investigating unconfirmed reports that a caravan has gone up in flames near the same location.
For the latest bushfire warnings and information, visit the NT Fire Incident map.
Conditions to persist into evening
Residents of several rural Top End communities had earlier been urged to prepare for the most dangerous fire conditions seen in the region for almost half a decade.
"This event is particularly quite extraordinary," Todd Smith from the Bureau of Meteorology NT told reporters at lunchtime on Thursday.
"It's the sort of event we only see once every five years or so."
Several major national parks — usually buzzing tourist hotspots at this time of the year — have been temporarily closed.
An additional water-bombing aircraft has been brought up from South Australia.
Mr Smith said the conditions were likely to persist throughout the afternoon before easing in the evening.
Winds are expected to lighten tomorrow, but very high or severe fire danger ratings will remain across the entire Top End before conditions ease into the weekend.
Mr Turner urged residents to remain vigilant and prepare their fire survival plans.
"It's too late to prepare your houses; all you can do is prepare yourself now," he said.
"It's imperative that your family know what to do in case of a fire.
"You need to understand what your fire survival plan is going to be and act on that."
