Military aircraft and naval ships will be deployed to support fire crews and stage evacuations in bushfire-ravaged areas of Victoria, the Federal Government says.
Eight emergency warnings remain in place for bushfires that have destroyed dozens of properties in the state's east and north-east, where four people remain missing.
Authorities have confirmed 43 properties — including homes and a primary school — have been destroyed by bushfire in Gippsland, where more than 400,000 hectares have been burned.
Prime Minister Scott Morrison and Defence Minister Linda Reynolds have agreed to deploy a fleet of aircraft and ships at the request of the Victorian Government.
As part of the deal, the Australian Defence Force will send Black Hawks, Chinooks, fixed-wing aircraft and Navy vessels for firefighting support and evacuations.
Earlier, Emergency Management Commissioner Andrew Crisp said 19 buildings had been destroyed in the farming district of Sarsfield, and 24 in the neighbouring town of Buchan.
An unknown number of properties have also been destroyed by fire in the Corryong area, near the NSW-Victoria border.
Situation remains dangerous
Aerial footage revealed Clifton Creek Primary School, in East Gippsland, was among the properties destroyed.
"The danger is not over," Mr Crisp said, describing the situation as "dynamic and dangerous".
"There's a lot of fire edge."
In the holiday town of Mallacoota, thousands of people huddled on the beach this morning as flames approached the area — but CFA chief officer Steve Warrington said the main bushfire front had since passed the town.
"I understand there was a public cheer down at the jetty when that was announced," he said.
But he said fires continued to burn in the area, and firefighters were still extinguishing houses on the outskirts of the town.
Samantha Corbett was on holiday in Mallacoota with her family and joined the thousands of people who sought shelter at the boat ramp as the bushfire hit the town.
She said "many, many spot fires" had started in and around the town on Tuesday afternoon and there was "a lot of smoke".
"The CFA are working tirelessly. They roll in, fill up then roll straight back out. Where we can we are clapping and cheering them on. I can't thank the emergency services here enough."
Thousands of people have been left without power in East Gippsland, which AusNet said may not be restored for days.
'There's a chance we've lost everything'
Thousands of holidaymakers and residents left East Gippsland for safer locations after authorities issued multiple warnings earlier this week.
Clifton Creek resident Shannon Hutchings's family of six left town for Lakes Entrance with their pets yesterday.
She believes the fire has since burned through their property twice.
"There's a chance we've lost everything," she said.
"We can't actually get on to the property [because] there's massive trees down in the way, so even if the fire's not in the area we can't actually get through.
As the prospect of homelessness looms, Ms Hutchings and her husband are among fire-affected residents working out where to stay and how to take care of their families.
"We're finding alternative places for our kids to go," she said.
"We have one [son] going to a nursing home at Paynesville because he has physical special needs — we can't provide for that here and we have none of his equipment," she said.
"We have two going to stay with some beautiful friends in Melbourne and we've yet to figure out whether we'll keep the fourth one with us."
Buildings razed on outskirts of Corryong
Fires are surrounding the town of Corryong, east of Albury-Wodonga in Victoria's north-east, where the CFA's Mr Warrington said people were experiencing a "high degree of anxiety".
He said there were numerous property losses on the outskirts of the town.
"It is isolated and we can get limited trucks in and out," Mr Warrington said.
He said the good news was that a cool change had passed through the town.
"So still a high degree of anxiety … and a lot of firefighting activity occurring again with numerous property losses, particularly on the outskirts of the town in Corryong."
An evacuation centre was set up at Corryong College.
Shalee Gherbaz said she had spoken to her brother in Corryong, who described the town as "an absolute mess".
"Fires are everywhere but the town was standing strong," Ms Gherbaz said.
In an update at 6:50pm, Luke Heagerty of the State Control Centre said people in the area should shelter indoors.
Lightning sparks new blazes in the Alps
Watch and act warnings have been issued after a band of lightning strikes started about a dozen new fires in Victoria's Alpine region.
Mr Warrington said those fires, pushing into areas near Mount Howitt, Mount Buller, and Jamieson, were also a cause for concern.
An updated emergency warning was issued at 3:50pm for a bushfire in the Upper Snowy Cluster near Corryong and Colac Colac.
Lightning strikes are still hitting Victoria's High Country and there are fears they could spark new fires.
Army, American experts called in to help
Commissioner Crisp said authorities were considering using helicopters to fly in food and other supplies to people cut off by the fires and related road closures.
"We still have communities that are isolated," he said.
"We're doing everything we can to get supplies down there to ensure that we can look after those people."
Fire services in the United States and Canada had been asked to provide "specialist aviation resources" to help firefighting efforts, he said.
Army personnel will join officers from the Metropolitan Fire Brigade (MFB) to conduct impact assessments in affected areas.