SYDNEY (AFP) - Firefighters were racing to tame an enormous blaze in south-eastern Australia on Monday with officials warning it could merge with others to create a "mega-fire" as weather conditions worsen.
Crews have been battling fires that flared in high winds and searing heat across the state of New South Wales last week with more than 200 homes so far destroyed and many others damaged.
While dozens of fires have been contained, 56 were still alight and 12 of them out of control, enveloping Sydney in a thick white smoke haze.
The main concern on Monday was near the town of Lithgow west of Sydney where a huge fire that has already burned nearly 40,000 hectares was threatening the communities of Bilpin, Bell, Clarence and Dargan.
Officials fear intensifying heat and winds on Tuesday and Wednesday could push it into another blaze at nearby Mount Victoria in the Blue Mountains and then move towards the populated areas of Katoomba and Leura.
"I don't think I've ever used the word mega-fire," said Rural Fire Service Commissioner Shane Fitzsimmons.
"But the reality is that the modelling indicates that there's every likelihood that in the forecast weather conditions that these two fires, particularly up in the back end of the mountains, will merge at some point."
Firefighters spent the night building containment lines to try and prevent this happening ahead of a predicted deterioration of weather conditions.
But the fire chief played down earlier suggestions that all communities in the Blue Mountains, where 76,000 people live, could be evacuated.
"We are not planning a mass evacuation of the Blue Mountains community," he said.
Instead authorities were taking "a very deliberate, a very considered, a very targeted approach to securing and protecting all the communities."
An emergency warning has been issued for the Blue Mountains village of Bell, where residents were urged to evacuate due to the immediate threat of fire.
Other township residents were told to shelter in their homes or warned that they faced several days of isolation without electricity.
Amid the worst fire disaster in the state for nearly 50 years, New South Wales declared a state of emergency on Sunday, which gives firefighters the power to forcibly evacuate people, with penalties for refusing.
Emergency Services Minister Mike Gallacher said every possible resource was being used, including firefighters being drafted in from interstate and the possibility that the military could also be deployed.
"Everything is being thrown at this, I can assure you," he said.