"You could hear houses exploding and trees going down. You could see the flames roaring up over the hill," resident Sue Brown told local media.

Authorities said blazes were threatening the town of St Marys, where many of the 600 residents were bracing to save homes from fires burning through scrub three kms (1.8 miles) away.

"It's not going to be long before St Marys is going to be impacted on by the ember shower and then the fire itself not long behind that," Tasmania Fire Service spokesman Danny Reid said.

In Victoria, bushfires sparked by lightning strikes continued to burn in rugged bushland in the northeast of the state, destroying more than 280,000 hectares (692,000 acres).

The fires levelled a ski lodge at the Mt Buffalo resort, which is still recovering from fierce 2003 blazes. Two of the largest fires had linked to form a 250-km front, although cooler weather was assisting a 2,000-strong force of firefighters, troops and 45 water-bombing aircraft before the forecast return of soaring temperatures later in the week.

HIGH DANGER

"Towards the end of the week we will be back in to having higher fire danger indexes and potentially extreme fire conditions," Department of Sustainability and Environment (DSE) spokesman Craig Ferguson told local radio.

In New South Wales state, a blaze lit by firefighters to rob bushfires of fuel leapt containment lines to destroy an ancient protected Blue Gum forest in the Blue Mountains, west of Sydney.

And southwest of the Australian capital, Canberra, firefighters were struggling to contain a wildfire fanned by strong winds near the mountain town of Tumut.

Another bushfire was also reported to have started west of Perth in Western Australia.

Firefighters say Australia faces an extreme fire danger this summer after a drought that has turned many rural areas into tinder boxes. Scientists fear climate change will bring more frequent higher temperatures and less rainfall to the country.

Bushfires are a regular feature of Australia's summer.