SYDNEY (REUTERS) - Thousands of firefighters burned grassland in eastern Australia on Monday (Dec 9) in a desperate bid to starve an anticipated new front of bush fires of fuel before forecast searing temperatures on Tuesday.
More than 100 fires remain ablaze in New South Wales and Victoria states, many of which have been burning for several weeks, including a single blaze that stretches more than 60km in a national park north of Sydney.
Conditions are expected to worsen from Tuesday, when temperatures are forecast to top 40 deg C and winds are expected to start picking up.
"We are expecting to see across large geographic areas high fire dangers," New South Wales Rural Fire Service Commissioner Shane Fitzsimmons told reporters in Sydney.
Seeking to minimise the threat, firefighters safely burned grassland around homes to remove fuel, he said. "Firefighters are doing kilometres and kilometres of back-burning operations, containment line establishment and consolidation.
"It is an enormous amount of work with more than 2,000 people out in the field."
Wildfires have killed at least four people, destroyed more than 680 homes and burned more than one million hectares of bushland across eastern Australia since the start of November.
Such fires are common in Australia's hot, dry summers, but the ferocity and early arrival of the fires in the southern spring this year have caught many by surprise. Experts have said climate change has left bushland tinder-dry.
Stoked by strong winds, several fires have combined into a single massive blaze that is threatening the region of Hawkesbury, about 50km north-west of Sydney.
The authorities have warned that the blaze is unlikely to be extinguished until meaningful rain arrives - which is not expected for at least three months - and forecasts indicate the fire could be pushed towards larger population areas.
"The big danger is if the winds come from the west, and that's exactly what is forecast," Hawkesbury City Mayor Barry Calvert told Reuters.
"People are trying to clear their gutters, clean up the leaves on the ground, anything they can do to keep their properties safe.
"We've opened the showground for people to move their animals, but many people here may have 20 horses and only two horse boxes so they can't move them quickly."
The wildfires have blanketed Sydney - home to more than five million people - in smoke and ash for more than a week, turning the daytime sky orange, obscuring visibility and prompting commuters to wear breathing masks.
The city, usually known for its sea breezes, clear skies and beach-dotted coastline, has made several appearances in the top 10 lists of the most polluted cities in the world.
Severe water restrictions begin in the harbour city on Tuesday.
Australia's worst bush fires on record destroyed thousands of homes in Victoria state in February 2009, killing 173 people and injuring 414.