Up to 100,000 Victorians have been urged to leave their homes ahead of worsening bushfire danger as the number of people missing in fire-affected areas rises to 28.

Key points: Six shires and four Alpine resorts will be covered by the state of disaster for a week

Six shires and four Alpine resorts will be covered by the state of disaster for a week The Premier said two people had died and 28 were missing

The Premier said two people had died and 28 were missing For the latest information, visit the Vic Emergency website

Fires in East Gippsland and the north-east of the state have burned through 800,000 hectares, or about 3.5 per cent of the state's area.

"We literally have hundreds and hundreds of kilometres of active edge, uncontained fire," said Victoria's Emergency Management Commissioner, Andrew Crisp.

"We've got a long, long way to go when it comes to fire danger in this state."

Mr Crisp said there were fears that a wind change tomorrow could cause fires that started in the High Country in recent days to merge with fires burning in East Gippsland.

CFA chief officer Steve Warrington said strike teams of five trucks each were being placed into communities that could be impacted by fire tomorrow in hot and windy conditions.

Fires have burned through about 3.5 per cent of Victoria's area. ( Facebook: DELWP Gippsland )

The preparations follow Victorian Premier Daniel Andrews's late-night declaration of a state of disaster for much of the eastern half of the state, the first such declaration ever in the state.

The Premier said the declaration provided "for formal evacuations of townships and areas" and sent a clear message that "if you can leave, you must leave", and would stay in place for a week.

The declaration gives the Government powers to take possession of private property to respond to the fires, control movement in and out of the disaster area and direct any of its agencies to perform or stop performing "any function, power, duty or responsibility".

Mr Andrews announced the declaration at a late-night media conference in Melbourne, after receiving an updated weather outlook on Thursday evening warning conditions would be even worse than earlier feared.

It covers a huge part of the state's eastern half, including parts of the East Gippsland shire, Mansfield shire, Wellington shire, Wangaratta rural shire, Towong shire, Alpine shire and the Mount Buller, Mount Hotham, Mount Stirling and Falls Creek Alpine resorts.

The state of disaster will remain in place for seven days over much of eastern Victoria. ( Supplied: Emergency Management Victoria )

A similar state of emergency declaration has also been made in New South Wales.

State Control Centre spokesperson James Todd there were "potentially 100,000 people across East Gippsland and the north-east that we'd like to get out of the area, out of the potential impact zone".

On Friday afternoon, Victoria Police Assistant Commissioner Michael Grainger said traffic on the roads out of fire-affected areas showed people were listening to the calls to leave.

"We certainly have very clear evidence that people have heeded the warning and we congratulate Victorians for doing that." he said.

As easterly winds blew smoke from fires in the state's east to Melbourne, the EPA's chief environmental scientist Andrea Hinwood urged people who were sensitive to air pollution to take precautions.

"Now is the time to put in place your treatment plan and, where possible, reduce your exposure to the smoke so that you protect yourself," Dr Hinwood said.

Earlier, Mr Andrews also revealed a second person had died in the crisis, but said it was too early to reveal details about their identity or the circumstances of their death.

He said on Friday morning the number of people unaccounted for in the East Gippsland region had grown from 17 to 28.

"I can confirm today that as at 9:30, there are 28 people that we cannot locate, and we are very concerned about their wellbeing," he said.

He said a number of those among the original 17 reported missing had been located yesterday.

Space to play or pause, M to mute, left and right arrows to seek, up and down arrows for volume. Watch Duration: 1 minute 31 seconds 1 m 31 s Entire streets of homes were reduced to rubble in Mallacoota.

Fifty fires burn across Victoria

Victorian fire crews are currently tackling 50 ongoing fires, mostly in East Gippsland and the state's north-east.

More than 780,000 hectares in Victoria have burnt so far. ( ABC News: Ben Jaensch )

Mr Andrews said he wanted to send a very clear message by using the disaster declaration, which was a recommendation of the royal commission into the 2009 Black Saturday bushfires.

"Essentially this declaration is the first time these powers have been used because we face unprecedented risk to life and property in coming days," Mr Andrews said.

"The fires are unprecedented in their size, their scale and the risk they pose to so many people right across affected communities.

A chimney was all that remained of a house destroyed in a bushfire at Cudgewa. ( ABC News: Matthew Doran )

"If you can leave, you must leave — if you don't we simply cannot guarantee your safety.

"Others may be put into harm's way in trying to protect you and you may well find yourself isolated and cut-off for an extended period of time following fire activity that will almost certainly occur tomorrow [Friday], Saturday and potentially into Sunday."

Emergency Management Commissioner Andrew Crisp said the coming days would bring unusually low humidity of under 10 per cent.

"What that means is that fires will travel at night," Mr Crisp said.

"People talk about fires five years ago, and that was not the case — generally fires overnight would settle down and you could, I guess, rest and regroup, but that's not what we're seeing.

"We've had examples of that over the last few weeks — the Marthavale fire ran 24 kilometres in one night, the Corryong fire nearly 30 kilometres."

Police and Emergency Services Minister Lisa Neville said the powers allowed for arrests if people refused to evacuate or follow other police orders, but authorities were not intending to penalise people.

Yesterday, Prime Minister Scott Morrison was confronted by angry protesters in the bushfire-hit town of Cobargo, in south-east NSW.

Space to play or pause, M to mute, left and right arrows to seek, up and down arrows for volume. Watch Duration: 44 seconds 44 s A group of Cobargo residents vent their anger at the Prime Minister.

Read the Premier's declaration:

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