Sydney  - The enormity of south-east Australia's forest fires was revealed Sunday, with as many as 40 people believed dead, hundreds of houses destroyed and swathes of countryside turned to ash.

The official death toll from Saturday's inferno stands at 25, but police expect the number to rise above 40 as they pick through the wreckage of homes, sheds and vehicles.

More than 400 fires have incinerated 150,000 hectares north of Melbourne, the capital of Victoria state.

"I'm absolutely horrified," Prime Minister Kevin Rudd said after flying to Australia's second-largest city. "This is an appalling loss of life, an appalling loss of property."

The bodies of six people were recovered from a burned-out car in Kinglake that apparently failed to outrace the smoke and flames.

A caller to local radio who identified herself only as Georgina said her town of Strathewen, near Kinglake, was unrecognizable.

"The school is gone, the hall is gone - some people left it too late. We've lost friends and we're just waiting for more - children, loved ones," she said. "They are calling out to houses and they can't hear people answering. Hang in there anybody that's listening and still cut off because they're coming."

Victoria state Premier John Brumby said strong winds in tandem with fiery temperatures combined to create tinder-box conditions a volunteer army of 30,000 firefighters backed by 37 water-bombing aircraft simply could not match.

He said he would discuss with Rudd drafting in the army to help tackle blazes that could burn for weeks.

"Some of these fires just weren't possible to control," Brumby said from the goldmining town of Bendigo, where deaths were reported. "You've had firefighters that were literally facing flames that were four storeys high."

Melbourne recorded its hottest February day on Saturday, with the temperature above 46 degrees. Inland of the port city of over 3 million people, the heat was even higher in the southern hemisphere summer.

Officials had warned of a possible repeat of the Ash Wednesday blazes in 1983 that left 75 people dead and razed 2,800 houses.

"It's just a day, I hope in my lifetime is never repeated," Brumby said. (dpa)