UPDATE, 5pm: The ADF will help respond to fires raging in Victoria's East Gippsland where four people are missing in blazes that have destroyed homes.
The state government has also announced a bushfire response taskforce it vows will avoid "red tape" in dealing with fallout from the blazes.
The developments come after lightning sparked more than a dozen new blazes in Victoria's alpine region on Tuesday.
More than 20 bushfires are now burning across Victoria, with flames ripping through more than 200,000 hectares in East Gippsland.
There was some good news amid the destruction, with a major fire front passing the coastal town of Mallacoota.
"I understand there was a public cheer down at the jetty when that was announced," CFA chief officer Steve Warrington told reporters.
The community remains isolated and 4000 people have been sheltering on the beach.
There are serious concerns for the welfare of a number of people in Victoria and we will be supporting these local communities in any way we can. Stay safe.— Scott Morrison (@ScottMorrisonMP) December 31, 2019
Some fires are still burning in the area.
Seven emergency warnings, the highest alert, remain in place across the region, with another in place for a fire straddling the northeast Victoria-NSW border at Corryong/Walwa.
Prime Minister Scott Morrison confirmed on Tuesday afternoon that the military will provide help.
"(The) federal government, especially our defence forces, are working together with the Victorian Government to respond to Victorian bushfires," Mr Morrison wrote on Twitter.
Emergency Management Commissioner Andrew Crisp said up to 40 military personnel will help assess the fire damage from Wednesday.Authorities are also considering other ways the military could provide support, such as fixed-wing planes and helicopters.
Requests for 70 firefighters have also been made to Canada and the United States.
Four people remain missing in the fires, with Premier Daniel Andrews earlier confirming they are not firefighters.
"We do have very real fears for their safety," Mr Andrews told reporters.
State cabinet's security and emergencies management committee met on Tuesday afternoon and established a bushfire response and recovery taskforce, to be led by Mr Crisp.
Victorian Emergency Services Minister Lisa Neville said the taskforce is aimed at ensuring "no barriers, no red tape, no bureaucracy" get in the way of meeting immediate needs and a broader response.
We are thinking of all those impacted by fires in Gippsland and NE VIC. Our crews are doing an amazing job both on the ground and in the air protecting communities. To everyone who is part of the effort keeping their fellow Victorians safe, THANK YOU 💛💚 pic.twitter.com/TFPU9VSaaC— ForestFireManagement (@FFMVic) December 31, 2019
Authorities have started the process of assessing how many properties have been destroyed by the fires, which grew rapidly overnight as self-generated weather systems sparked dry lightning.
So far, 19 structures have been confirmed destroyed in Sarsfield and 24 in Buchan.
Victorian Education Minister James Merlino has confirmed Clifton Creek Primary School in East Gippsland has been destroyed by fire.
Thousands of people are seeking support at about a dozen relief centres in the state.
Milder weather is expected in East Gippsland in the next few days, but Mr Crisp said people cannot relax.
"Everyone need to remain vigilant," he said.
The Bureau of Meteorology says the temperature spiked at 49C at Mallacoota around 8am.
The bureau believes that fire-affected air, or fire itself, moved past the weather station at the time, with the mercury dropping to 24C just 10 minutes later.
The blazes have cut power to homes, with AusNet Services reporting 5700 properties without electricity in East Gippsland, with another 1800 in northeast Victoria.
The energy company expects it could take days to restore power.
UPDATE, 1.30pm: Jessica and Peter Tarpey, like so many residents in Victoria's East Gippsland, don't know if they have a home to go back to.
Sitting in a bushfire relief centre at Bairnsdale, the Bruthen couple doesn't want to take any chances.
Four people are missing and seven emergency warnings remain in place for East Gippsland as fires rip through the region.
The Tarpeys have survived bushfires before and knew they had to get out while they could.
"(There's) no word about whether the house is still there or our neighbour's houses are still there. No word about some of our neighbours," Jessica Tarpey told AAP on Tuesday.
"We knew this one was going to be bad. We've been saved by helicopters before. We're not going to leave it to chance this time.
"We just have to take it as it comes."
Fellow evacuees Iven Martinovic and partner Dianne Abdullah fled their independent living unit at Bruthen late on Monday afternoon, with budgie Ned Kelly in tow.
"It was pretty god damn bad," Mr Martinovic said.
"We were oblivious to what was going on. The local policeman come and he said 'would you like to go?'."
They don't expect to be allowed home for days.
"We're not worried about if the unit did go or what we might have lost, as long as we've got the three of us. You can always replace things," Mr Martinovic said.
It came as East Gippsland Shire Council Mayor John White surveyed the bushfire damage at Sarsfield, near Bairnsdale.
"(It's) absolutely gut-wrenching," he said.
Properties have been lost but Mr White was amazed to see so many still standing.
"Originally I looked at some of the houses .... I couldn't believe the number that have been saved, the fires been burnt right up to them," he said.
"And then I've gone a little bit further and a lot of the houses have been lost."
In the far eastern corner of the state, thousands of residents at Mallacoota have been told to shelter near the water as a bushfire hit the town.
Fires have ripped through more than 230,000 hectares in East Gippsland so far, after more than 200 began on Monday and another 60 early on Tuesday morning.
UPDATE, 11.25am: Four people are missing and defence force support has been requested as fires rage through Victoria's East Gippsland, destroying homes.
Premier Daniel Andrews confirmed the missing people at a press conference on Tuesday morning in Melbourne.
"There are four people unaccounted for. We can't confirm their whereabouts," Mr Andrews told reporters.
The missing people are not firefighters, he said.
Mr Andrews had been text messaging with Prime Minister Scott Morrison on Tuesday morning about support for the recovery effort.
"I'll speak with him after we finish here. We've made some requests to the (Australian Defence Force) for their support, both in terms of making damage assessments but also some of these isolated communities can be accessed by sea," Mr Andrews said.
"We have a range of plans in place ourselves but there may be ways in which the ADF can support us."
More than 1,000 firefighters worked in challenging conditions in East Gippsland yesterday & overnight. Here is a look at scenes from East Gippsland over the last 24 hrs. Please continue to monitor local conditions and warnings via https://t.co/XZY9uEcO6X and stay safe #VicFirespic.twitter.com/FyGUL062r3— VicEmergency (@vicemergency) December 30, 2019
Requests for the help of 70 firefighters have also been made to Canada and the US, Mr Andrews said.
Authorities have started the process of assessing how many properties have been destroyed by the fires, which grew rapidly overnight due to self-generated weather systems sparking dry lightning.
More than 200,000 hectares of land is burning in East Gippsland, Emergency Management Commissioner Andrew Crisp said on Tuesday.
As of Tuesday morning, the coastal town of Mallacoota was being hit by fire, sending at least 4000 people to the beach for shelter.
CFA chief officer Steve Warrington said he had talked to firefighters on the ground and they were seeing conditions not seen for a long time.
"I spoke to them again this morning, 'It scared the crap out of us,' that's from our firefighters," Mr Warrington told reporters.
"Don't think our firefighters, because they wear a uniform, are superheroes. They're people. They're working with our communities to make sure they're safe as well."
#Mallacoota sky has lightened up to a pale orange now. Some smoke blown away by strong cool wind. Somewhat perplexing that we’re hearing of so much damage around town but haven’t seen the actual fire front ourselves. Then again, there are reasons we picked this place to defend pic.twitter.com/X4VJBvhpKv— Brendan (@brendanh_au) December 31, 2019
EARLIER: Fire has hit a Victorian coastal holiday town and people are being told to go into the water as warning sirens sound.
Authorities believe about 4000 people are still at Mallacoota, which is being hit by fire about 8.30am on Tuesday.
"Everyone is hopefully down on the foreshore in the water," Don Ashby told ABC on Tuesday morning as emergency sirens sounded.
The fire has cut power to the town, with AusNet Services reporting 5700 properties in East Gippsland without electricity due to the fires, and another 1800 in northeast Victoria also down.
Mobile and landline phone lines are also down in parts.
"It's not pleasant, it's pitch dark here and the emergency vehicles have disappeared from sight," resident and local community radio presenter Francesca Winterson told ABC Gippsland.
"The power's been out here a long time and we've run out of solar.
"My home's in the fire path, I won't have a home, that's just the way it's going to be, we have to try and be calm."
Properties have been lost in Victoria's east as out-of-control bushfires rage, but it's too early to confirm how many, Emergency Management Commissioner Andrew Crisp says.
The fires grew rapidly overnight due to winds and lightning strikes and have ripped through more than 200,000 hectares in Victoria's East Gippsland, it was estimated early on Tuesday morning.
"There are property losses and there's property losses across East Gippsland, but at this stage it's too early to confirm in which particular locations," Mr Crisp told ABC News.
Seven emergency warnings, the highest alert, remain in place across East Gippsland and there is another in place for a fire straddling the northeast Victoria-NSW border at Walwa/Corryong.
Three strike teams are looking after thousands of people still believed to be in coastal Mallacoota, Mr Crisp said.
"We are naturally very concerned about communities that have become isolated and to get an appreciation about other losses there could be we'll be putting helicopters up doing reconnaissance flights," he said.
Incident controller Chris Eagle told ABC Gippsland that lightning in the region sparked hundreds of new fires overnight.
By Monday evening, as temperatures soared and the fires started creating their own weather systems, about 1000 firefighters were working on the blazes.
The satellite took an image of some of the heat tracks, it's several hours old now, but it's probably close to at least 60 per cent larger than it was yesterday, so much, much larger and that starts right up north of GelantipyIncident controller Chris Eagle
Towns including Cann River, Bruthen and Orbost had been impacted by the fire and assessment teams will be sent to survey the damage.
The Princes Highway is closed between Bairnsdale and Genoa. The fire has also crossed Great Alpine Road at Ensay.
A cool change swept through the region after extreme heat on Monday, but windy conditions remain, further fuelling the fires and spreading ash.
Mr Eagle said the fires were generating their own wind systems, which delayed the arrival of the cool change.
Victorian Premier Daniel Andrews attended a briefing at the State Control Centre, cutting short his holidays.
Fireworks displays planned in the region for New Year celebrations have been cancelled because of the fire risk.