Parts of southern Australia were under threat of a severe wildfire, with Victoria State facing its worst conditions in nearly five years, according to the Associated Press.
Emergency warnings were declared for nine blazes that were burning out of control in Victoria State, where homes were lost near Gisbourne.
Weather temperatures were tipped to reach 40 C (104 F) on Sunday.
The New South Wales Rural Fire Service said a military training exercise sparked the largest of the wildfires that have ravaged the Australian state.
Fire investigators found that a massive fire near the city of Lithgow, west of Sydney, began on 16 October at a nearby Defence Department training area, and that the blaze was started as a result of live ordnance exercises at the army range.
The fire has scorched 47,000 hectares (180 square miles) and destroyed at least three houses, but no injuries or deaths have been reported.
The Defence Department declined to comment on the investigators' findings, but confirmed earlier that an explosive ordnance training exercise was conducted on that date
Prince Charles has sent a message of support to the firefighters tackling wildfires in Australia, some of whom he met on a visit to Bondi Beach last November.
The message to the New South Wales Rural Fire Commissioner said: "I just wanted you all to know that you are very much in my thoughts as you battle courageously against such appalling bushfires around Sydney.
It continued: "My wife and I so greatly admire the selfless service you provide in such incredibly dangerous and distressing circumstances and our hearts go out to all those – including firefighters – who have lost their homes in this terrible conflagration."
The Prince has also made a contribution to the Australian Red Cross "to help them support people affected by the bushfires".
Firefighters in New South Wales, Australia have said that 16 schools will be temporarily closed as a result of the wildfires engulfing the state.
All of the affected schools are in the Blue Mountain and Hawkesbury areas around 50 miles west of Sydney, the state's Rural Fire Service said.
Firefighters say they have "never before have we seen the extent of damage and destruction" of wildfires in the Blue Mountains and Hawkesbury areas of New South Wales, Australia so early in the year.
A spokesman for the Rural Fire Service said that 73 wildfires are still burning across the state and that 29 of these have not been contained.
He said that a blaze on the western edge of the M1 motorway had temporarily closed off traffic in one direction, and that it would take "many hours of work" to bring it under control.
A list of schools to be closed as a result of the wildfires will be published shortly, he added.
Thousands of firefighters are continuing to battle dozens of wildfires raging in New South Wales as weather conditions are set to worsen.
There are 59 fires burning across the state, with 19 out of control, according to the Rural Fire Service (RFS)
RFS Commissioner Shane Fitzsimmons said: "We are entering what is typically the hottest and driest period of any given day.
"The temperatures are climbing and are expected to climb and maintain their peak throughout the coming hours. The worst of the weather is still to come."
Officials warned that a storm heading towards the fire front in the Blue Mountains of New South Wales would increase the fire danger.
The storm is expected to bring up to two millimetres of rain, lightening and strong winds.
Dramatic footage has shown Australian firefighters driving into the heart of wildfires as they attempt to stop out-of-control blazes from merging into a massive united inferno.
Fire crews have been battling the flames on a grand scale in the Blue Mountains in New South Wales but conditions are expected to worsen over the next 48 hours.
ITV News' Ben Chapman reports:
Wildfires are spreading across a 200-mile stretch of bushland in Australia's Blue Mountains and edging closer to Sydney's suburbs.
Firefighters are tackling more than a dozen separate blazes that are out of control across New South Wales, which they fear could merge into a giant inferno.
ITV News' Ian Williams reports:
Firefighters battling the wildfires in New South Wales raced towards a national park that had caught ablaze, but were forced to retreat in the face of flames climbing higher than 100 feet.
This gripping video was shot by Ryan Taylor, who is a volunteer firefighter for Lake Munmorah Rural Fire Brigade, part of the New South Wales Rural Fire Service.
The NSW Rural Fire Service said lightning is moving across the state, although no significant rainfall is expected to help alleviate the wildfires.