An extra 3,000 army reservists have been called up to help tackle Australia's bushfires, with the situation expected to worsen over the weekend.
The country's Prime Minister Scott Morrison confirmed the death toll had risen to 23 - with two more fatalities confirmed on Saturday - and warned "we are facing another extremely difficult next 24 hours".
"The priority of this deployment is to assist ensuring the safety of life, to support the evacuation of affected people, particularly in isolated communities and provide assistance to isolated communities and support state managed evacuation centres," he said.
"It is to move in and to move forward, particularly in areas that have been devastated by fire to support the immediate response needs there and the recovery effort that will also follow."
"In recent times, particularly over the course of the balance of this week, we have seen this disaster escalate to an entirely new level," he added.
The @CopernicusEU #Sentinel3 ??????? carries 2 different sensors:
The SLSTR (Sea and Land Surface Temperature Radiometer) [yellowish image] and the OLCI (Ocean & Land Colour Instrument)
In today’s acquisition they enable to have a different views of the #nswfire #vicfires ????
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— Copernicus EMS (@CopernicusEMS) January 4, 2020
Fire tornadoes and dry lightning have sparked even more blazes, as temperatures soared to new highs on Saturday - 48.9°C in Penrith, 45°C in Sydney and 44°C in Canberra.
Penrith, a suburb of Sydney, was believed to be the hottest place on Earth on Saturday.
It was the hottest day ever recorded in greater Sydney.
The New South Wales Rural Fire Service has updated emergency warnings, telling those who have not evacuated at-risk areas: "It is too late to leave. Seek shelter as the fire approaches."
EMERGENCY WARNING – Border Fire (Bega Valley LGA)
If you are in the area of Womboyn, Kiah, Narrabarba, Towamba, Burragate, Eden and surrounds, you are at risk. It is too late to leave. Seek shelter as the fire approaches. #nswrfs #nswfires #alert pic.twitter.com/fHbAOc9fvg
— NSW RFS (@NSWRFS) January 4, 2020
Strong winds and high temperatures are expected to bring flames to more populated areas, including the suburbs of Sydney.
New South Wales Premier Gladys Berejiklian said her state is facing "another terrible day" and called on people in areas threatened by the fires to leave while they can.
"I'm pleased to say that we've never been as prepared as we are today for the onslaught we're likely to face.
"All of the major road networks are still open but we can't guarantee that beyond the next few hours. So there are still windows for people to get out."
The fire broke containment lines Friday and was described as "virtually unstoppable" as it destroyed buildings and burned through more than 14,000 hectares (35,000 acres) of Flinders Chase National Park.
New South Wales Rural Fire Service Deputy Commissioner Rob Rogers said more than 130 fires are burning in the state and at least half of those are out of control.
There will be a statewide Total Fire Ban in place tomorrow. Although the fire danger will be less than today, we are still expecting moderate winds from the south to southeast to impact on the more than 150 fires burning across the state. #nswrfs #nswfires pic.twitter.com/8o5EvvqAJ7
— NSW RFS (@NSWRFS) January 4, 2020
"We are unfortunately very likely to lose homes but we will be very happy and call it a success if no lives are lost," he said.
A total of 48 fires are burning across almost 320,000 hectares (791,000 acres) in Victoria state and conditions are also expected to worsen with a southerly wind change.
"We still have those dynamic and dangerous conditions, the low humidity, the strong winds and, what underpins that, the state is tinder dry," Victoria Emergency Services Commissioner Andrew Crisp said.
Thousands have already fled fire-threatened areas in Victoria and Mr Crisp urged more people to leave.
Victoria police reported heavy traffic flows on major roads and praised motorists for their patient and orderly behaviour.
On Friday, the Irish embassy in Australia advised citizens to "keep informed of the latest evacuation orders and developments".
It also encouraged them to register their travel and residence information.