Eighty-four people are confirmed dead, surpassing the state's toll of 75 in the 1983 Ash Wednesday blazes, as Prime Minister Kevin Rudd described the inferno as ‘hell's fury’ unleashed on Victoria.

The number of dead may rise as blazes continue to ravage the state as 3,000 firefighters struggle to contain seven major fire fronts, the Sydney Morning Herald said on Sunday.

More than 200,000 hectares of area has been affected by the fires that have left at least 640 homes destroyed in more than 400 fires in every part of the state, it said.

"Hell and all its fury has visited the good people of Victoria in the last 24 hours," Rudd told reporters in the fire-ravaged Yarra Valley.

"This is an appalling tragedy for Victoria but because of that it's an appalling tragedy for the nation," he said.

The Marysville and Kinglake townships have been nearly wiped out as police suspects some fires were deliberately lit.

However, investigators would not be able to establish how many of the fires were arson-related until the scenes are surveyed and the origin of the blazes located, the Herald quoted a police spokeswoman as saying.

The largest fire front is in the Kinglake area, where over 120,000 hectares have been burnt and at least 12 people have been killed as authorities began a search for bodies on Sunday.

Thousands of survivors flocked community halls and other make-shift accommodation as firefighters battled to control the inferno.