The death toll from Victoria's bushfires has risen to 66 and 640 houses have been destroyed.
The true extent of the damage will not be known until authorities can enter some of the towns which are suspected to have been destroyed completely.
Twenty-six fires continue to burn across Victoria; 12 of those are out of control.
The biggest fire covers 210,000 hectares and is north of Melbourne.
Bushfires are continuing to burn out of control near Murrindindi and Kilmore north of Melbourne.
The Kinglake region, about 80km north of Melbourne, has been the worst hit - 550 homes have been razed and 55 deaths had been reported in the area as of 6pm (AEDT) on Sunday.
According to residents, much of the town of Kinglake, which suffered eight deaths, has been destroyed.
Virtually the entire township of Marysville in the Yarra Valley was destroyed overnight on Sunday as the East Kilmore and Murrindindi Mill fires merged into a massive 120,000 hectare inferno, now known as the Kinglake Complex.
Aerial pictures shown by the ABC on Sunday show street after street of completely destroyed houses in the town, population 600.
The fires have also burnt through Buxton and Narbethong.
Authorities believe some of the blazes were deliberately lit and police say arsonists could face murder charges and a maximum 25 years in prison.
Ten people remain in a critical condition in hospital with serious burns.
Firefighters say 640 homes have been destroyed in the fires across Victoria State so far this weekend, the vast majority in the worst-affected areas north of Melbourne.
Prime Minister Kevin Rudd has announced a joint federal-state $10 million emergency relief fund for the victims.
Mr Rudd, visiting the burnt-out region, said there had been an appalling loss of life.
"Hell and its fury have visited the good people of Victoria," he said.
Fire crews are beginning to assess the damage from the fires in Gippsland, east of Melbourne.
The fires, near Warragul and Traralgon, are no longer posing a direct threat, but communities have been urged to stay vigilant.
Other fires are burning near Walhalla and Dargo, but are not posing a threat.
More than 300,000 hectares of private and crown land has been burnt out, while flame and smoke-choked roads are littered with deserted cars.
Mr Brumby said volunteer firefighters and aircraft were coming in from NSW and South Australia, while the Australian army will also be brought in to help.
Power has been cut to 27,000 across northern Victoria as a result of the bushfires.
Hugo Armstrong from Australia's Powercorp says it may be sometime before power is restored.
Australia's worst bushfires occurred on Ash Wednesday in 1983, when 75 people were killed, 47 of them in the state of Victoria.
Temperatures in Melbourne reached 46.4 degrees Celsius on Saturday - the highest on record.
The bushfire threat for New South Wales has waned with the chance of unpredictable winds accompanying a forecast cool southerly change the greatest remaining concern for authorities.
While temperatures peaked in the mid-40s in parts of western NSW, including 46 degrees at Ivanhoe, Sunday's forecast scorcher did not reach its expected severity.
Nevertheless, some 53 bushfires across the state burnt more than 6,500 hectares of land.
A total fire ban is in force across most of the state.