A family-of-three is missing and more than 20 homes are potentially lost as out-of-control bushfires continue to burn across Victoria.

The Longwood fire has burnt through more than 48,000 hectares and forced residents across dozens of towns to evacuate their homes.

Another major fire, the Walwa blaze, has burned through more than 17,000 hectares in the state’s north-east.

LIVE UPDATES: Local institution cancelled as destruction laid bare

An out-of-control blaze in Longwood has burnt through more than 48,000 hectares. (Nine)

Authorities hold concerns for a man, woman and child who firefighters spoke with at a home in the Longwood East area yesterday morning.

Crews returned to find the property destroyed by fire yesterday afternoon.

“Those three people, we do not know at this point in time where they may be,” Victoria Police Deputy Commissioner Bob Hill said this morning.

“At this point in time, I’m not suggesting we’ve seen three people perish, all I’m saying is these three people are unaccounted for.”

Emergency services are currently unable to investigate their disappearance as the area is still a danger zone but the trio remain unaccounted for this evening.

READ MORE: Small town of Ruffy unrecognisable as fire destroys homes

The fire has forced dozens of towns to evacuate their homes. (Nine)

Victoria’s Emergency Management Commissioner Tim Wiebusch confirmed “community and residential” properties have been destroyed in the Longwood fire.

Many of these losses have been in and around the Ruffy area.

Wiebusch said the number of properties destroyed could not yet be confirmed, but that the Ruffy community centre and telephone exchange had been destroyed, along with multiple homes.

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Firefighters have battled low visibility on the fire ground at Alexandra. (Nine)

Wiebusch said firefighters would face “challenging and difficult” conditions across the state.

“Victoria is in the midst of a severe to extreme intensity heatwave, which is now being matched with damaging winds and storms today, that will result in our state seeing catastrophic and extreme fire danger,” Wiebusch said.

“That means that any fires that are in our landscape already or those that start will be uncontrollable, unpredictable and will be very fast-moving.”

CFA Captain George Noye, who was visibly emotional this afternoon, told 9News the fire has cleared homes, buildings and livestock.

“There’s not much left. It’s just ash,” Noye said.

“If we go away to a lot of fires and we see this happen with communities, it’s devastating.”

Earlier this morning, Noye said the damage in Ruffy looked like “an atomic bomb has gone off”.

“We’ve lost the old school, the old Ruffy produce store is gone, three houses on the main street, we’ve lost countless homes across the area,” he told ABC.

“Ten of my firefighters that I know of have lost homes.”

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Property losses in Ruffy in the Longwood bushfire. (9News)

There are fears the potential impact zone of the Longwood fire could creep towards Melbourne’s fringes due to a potential wind change expected at about 8pm tonight.

Approximately 1200 to 1600 hectares of a pine plantation have been destroyed by the Walwa fire, though no property there has be lost as yet.

A total fire ban has been declared across the whole of Victoria for tomorrow.

Temperatures are expected to cool across most of the state tomorrow, but the mercury is expected to nudge 40 in some areas including Geelong and Mildura.

A high of 26 degrees is forecast for Melbourne tomorrow.