Police say the number of people killed in the bushfires raging through south-eastern Australia has risen to at least 84.

A firefighter looks on helplessly at a raging bushfire

It makes it the greatest fire disaster in the country’s history.

Many of those killed were trapped in cars trying to flee a huge inferno north of the city of Melbourne.

Survivors described “walls of flames” destroying houses and engulfing entire towns.

More than 640 homes have been destroyed by the fires, many in the area of Kinglake, north of Melbourne.

Victoria state premier John Brumby said troops will be used to help put out the blazes.

They will join thousands of volunteers after Mr Brumby accepted Australian Prime Minister Kevin Rudd‘s offer of extra help.

Mr Brumby said the army would provide “logistics and support” which would include building firebreaks.

Conditions were said to be better on Sunday but several dangerous fires were still raging, threatening a number of townships.

Fires tore through forests, farms and towns in Victoria on Saturday as temperatures hit 46Cand wind speeds picked up.

The blaze was so big it was visible from space. NASA released satellite photographs showing a white cloud of smoke across the whole of South East of Australia.

Australia’s previous worst bushfires occurred in 1983 when 75 people were killed, also in the state of Victoria.