This weekend's bushfires in Victoria are more deadly for the state than Ash Wednesday, as the death toll stands at 50 and is expected to rise.

The human toll is compounded by the loss of at least 640 homes but the true extent of the damage is not yet clear.

Authorities suspect arsonists are responsible for some fires.

Six of the confirmed dead have been found at Kinglake, six at Kinglake West and four each at St Andrews and Wandong, all north of Melbourne.

Five people are dead in Callignee, three in Hazelwood and one in Jeeralang. More bodies have been found at Humevale, Bendigo, Upper Callignee, Long Gully, Strathewan and Arthurs Creek.

Victoria's deputy police commissioner Kieran Walshe says the death toll will rise and it is expected to include children.

The town of Marysville north of Melbourne has been all but destroyed and there are grave fears for nearby Kinglake, where residents have described a "town on fire".

A fire in Beechworth in the state's north-east has grown to around 25,000 hectares after the wind changed from west to south-west around midday. Houses there have come under ember attack and power lines are also under threat.

Meanwhile the blazes which have razed homes just north of Melbourne have grown to more than 210,000 hectares and are burning towards Glenburn, Taggerty and Rubicon.

'Helpless'

Emergency Services Commissioner Bruce Esplin said he felt numb after watching fires leave authorities almost helpless.

"Nature gave Victoria a beating of unimaginable proportions," he told ABC Local Radio.

He says the deaths are an awful reminder that people should be prepared to leave their homes early.

"Bushfire risk is real, it's horribly real. It can become an awful reality with little warning and no second chance," he said.

"You can rebuild a house but you can't rebuild a life."

He says exhausted fire fighters - both paid and volunteer - may not get much chance to rest.

"Summer's not over yet, this fire's not over yet. Fire services aren't just going round blacking out, they're trying to put fires out.

"The Victorian summer is a long way from over and there'll almost certainly be more bushfires."

Murrindindi Shire Mayor Lyn Gunter is among residents believed to have lost homes in the Flowerdale area.

Fire authorities are struggling to get into the centre of the towns to survey the full scale of the damage, and ambulance services in Kinglake say they are being overwhelmed by calls for help. Police say 514 homes in Kinglake have been lost.

ABC reporter Jane Cowan earlier described the horrific scene in Marysville.

"We were in the main street and it's like a warzone, like a bomb has been dropped on the entire township," she said.

"People there are in an absolute state of shock. Most people had already left, but the people, I'd say about 30 people that are still left and had spent the night sheltering on the Football Oval there, are just completely dazed.

"[They are] walking around the streets with rugs around their shoulders because it's actually getting cold here now, if you can believe it.

"There are stories of households that sheltered three families in one house. Of gas bottles from nearby houses exploding and then piercing their houses and then those houses catching fire as well. It's an absolute warzone.

"People are saying that there are bodies in the town, terrible stories of for instance a woman who was found in her car this morning, obviously, was trying to escape. She didn't make it. She had her crockery on the seat beside her in the car."

Last house standing

Great-grandmother Olga Tuckerman said she had God on her side when a blaze swept through Bendigo's western suburbs, in central Victoria.

She said she returned to Bendigo today to find her house standing alone amid a mass of smoking, razed houses.

"Someone up there was looking out for me," Mrs Tuckerman told Australian Associated Press.

But her neighbours were not as lucky. Jean Perkins, 72, returned to find smoking ruins where her house used to be.

"I said a couple of prayers yesterday - please keep my home Lord, but he wanted to take mine for some reason," she said.

An ABC reporter in Labertouche today told Local Radio people were shell-shocked after the Bunyip fire, east of Melbourne, had engulfed surrounding forests and property yesterday.

She said high winds pushed walls of fire over houses in the area at enormous speed yesterday. She described an interview she was conducting when the wind changed in the middle of the Saturday.

"We felt a strong gust of wind during the interview, we stopped the interview and in almost an instant the fire came over," she said.

"You can be prepared as you like but nothing gets you ready for that."

Lightning threat

There is cool weather forecast for the next few days which is expected to make conditions easier for fire fighters. But with no prospect of decent rainfall, lightning strikes could start more fires.

John Coleridge from the Alfred Hospital has likened the influx of burns victims to the aftermath of the Bali bombings.

"Everybody was called in large numbers," he said.

"And they would have burns and blast victims there, so that would be the only parallel that I can think of."

The Victorian Health Minister, Daniel Andrews, says 78 people have been admitted to hospitals throughout the state with various burns, and hundreds of others have turned up at emergency departments, with less serious injuries.

Arson suspected

CFA officials say they suspect at least one arsonist of relighting fires that had burnt out, and lighting new fires ahead of existing fire fronts.

"To think you could do that yesterday in those conditions when you knew that any fire you lit had the potential to cause severe losses and death, I think that's something that is just appalling," said Victorian Emergency Services Minister, Bob Cameron.

Federal Opposition Leader Malcolm Turnbull added to the calls to hunt down firebugs.

"It is difficult to imagine a more horrific crime than arson," he said in Sydney.

"All Australians will expect the authorities to want the police to... be absolutely relentless in tracking down those responsible and ensuring they're brought to justice."

Victoria has accepted an offer from the Federal Government for the Defence Force to be drafted in to help with the fires.

The Emergency Services Minister, Bob Cameron, says the army has bulldozers and other equipment that can be used to strengthen containment lines.

If you can see flames call the Country Fire Authority's information line on 1800 240 667.

Tune into a special edition of ABC News tonight at 7pm on ABC1 and streamed live on ABC News Online.