The airport in Australia's capital city, Canberra, has been shut down as bushfires threaten the region.A heatwave sweeping the nation's south-east caused existing blazes to flare up again on Thursday, officials said.
Meanwhile there are reports a firefighting aircraft may have crashed in the Snowy Mountains, two hours south of the capital.
The New South Wales (NSW) Rural Fire Service said it had lost contact with the large air tanker shortly after 13:30 local time (02:30 GMT) on Thursday.
Helicopters are searching the area and emergency services have rushed to the scene.
There are more than 80 blazes raging across the state of NSW as hot and windy conditions return to the region.
In Canberra, officials issued emergency warnings urging people to stay away from the airport as two blazes threatened to breach the airfield's perimeters.Fire threat returns
Since September, Australia has battled an bushfire crisis which has killed at least 30 people.
More than 10 million hectares - an area almost the size of England - have been destroyed in blazes. The most affected states are NSW and Victoria.
Recent days of thunderstorms and rain across fire grounds had helped halve the number of blazes burning in the region since the start of the year.
Fires 'far from over' as storms sweep Australia
However, fire chiefs warned that the sporadic rain would only provide short-term relief ahead of the return of dangerous conditions.
Temperatures in Sydney on Thursday soared past 40C (104F) in the city's west.