A worldwide plea to help Australian firefighters contain catastrophic bushfires raised over AUS$25 million (US$ 17 million) on Monday, as the country's vast areas of land falls into a seemingly endless inferno.

Seaside towns on the east coast were plunged into darkness, ash rained down on rural communities, and major cities were again shrouded in breathtaking smoke, even as shocked Australians sought to regroup in a sea of cooler air and light rain.

The weekend marked some of the worst days in the deadly bushfire crisis in the country, with hundreds of properties being lost and the death toll rising to 24, including a man who perished late Saturday trying to rescue a friend inside a burning house.

Popular comedian Celeste Barber took advantage of her social media success to promote a Facebook firefighters fundraiser that had reached its goal of AUS$25 million in just three days with donations coming from around the globe.

American pop star Pink assured the firefighters that she would contribute US$500,000, a pledge matched by Australian actress Nicole Kidman.

Ashleigh Barty, world number one tennis player, vowed to turn over all her winnings from the Brisbane International tournament this week - around US$ 250,000 - to the Red Cross.

About 200 fires continued to wreak havoc across the country on Sunday, many out of control, although as temperatures dropped, only a few triggered emergency warnings.

Millions of distressed residents everywhere struggled to come to grips with a catastrophe that took place on a near-continental scale, unfurled over months, altering everyday life.

According to New South Wales Premier Gladys Berejiklian, the people of Australia are now in "uncharted territory."  Officials struggled to keep up with the extreme crisis that has now scorched an area nearly the size of Ireland, she said.

Although bushfires are normal in dry summers in Australia, climate change has pushed up land and sea temperatures, leading to hotter days and extreme fire seasons.

Australian Prime Minister Scott Morrison's handout on Saturday revealed the country's largest military call-up in recent years, mobilizing up to 3,000 reservists to help the weary firefighters.

Warships, military reservists and aircraft have been repurposed to assist with Australia's biggest maritime evacuation since World War II - carrying to safety some of the 4,000 people trapped for days on Mallacoota's foreshore, halfway between Sydney and Melbourne.

Thousands of people were homeless up and down the coast, and many more were considering an uncertain future.