Australians fled to a beach yesterday to escape a "fireball" burning through their small town towards the sea, as firefighters battled major bushfires across three states and marked homes which could not be saved.

Residents at Four Mile Creek on the island state of Tasmania said a wall of flames swept through their hamlet, destroying one house, and cutting off evacuation routes.

"The best bet is head to the beach and hope the fire brigade and fire fighters are doing their job," resident Shane Hodge told reporters as the bushfire cut off the seaside village.

By late afternoon a wind change turned the fire back on itself and light rain was reported.

In the nearby Tasmanian village of Cornwall firefighters stood their ground to save more properties.

"They just stood in the flames with hoses and not a lot more," ABC radio reported. Residents whose homes were spared hugged fire crews after the inferno passed.

Earlier authorities placed red tape across driveways of houses in Cornwall and nearby St Marys, marking them as homes they would be unable to save.

"If a property has trees right up to the back door, then it's going to put lives at risk and we have to declare those houses as undefendable," Tasmanian Fire Service spokesman Michael Watkins said.

The St Marys blaze engulfed 14 houses in the coastal town of Scamander on Monday and has moved to threaten three more rural communities, driven by winds gusting at 50 km per hour.

In Victoria state, more than 4,000 Australian and New Zealand firefighters were battling 11 blazes sparked by lightning strikes that have burnt 420,000 hectares of rugged mountain bushland and which threaten several towns.

As temperatures soared again after two days of relatively cool conditions that aided control efforts, authorities were considering calling for reinforcements from the United States.

Firefighters were scrambling to save the historic Mt Buffalo Chalet in Victoria's northeast as strong northerly winds pushed a blaze towards the grand 96-year-old building.

Sign up to our free newsletters

Get the best updates straight to your inbox:
Please select at least one mailing list.

You can unsubscribe at any time by clicking the link in the footer of our emails. We use Mailchimp as our marketing platform. By subscribing, you acknowledge that your information will be transferred to Mailchimp for processing.