Officials are searching for bodies among the charred ruins of more than 100 homes and other buildings destroyed by wildfires in the Australian island state of Tasmania.

Acting Police Commissioner Scott Tilyard said Monday no casualties had yet been reported. But it would take time before officials were certain that no one had died in the blazes that have razed 20,000 hectares of forests and farmland across southern Tasmania since Friday.

Police have concerns for about 100 people reported missing. Tilyard said 11 teams were searching ruins in places including the small town of Dunalley, east of the state capital of Hobart, where around 70 homes were destroyed.

"Until we've had the opportunity to do all the screening that we need to do at each of those premises, we can't say for certain that there hasn't been a human life or more than one human life lost as a result of these fires," Tilyard told reporters.

Three fires continued to burn out of control in southern Tasmania and in the northwest Monday.

Prime Minister Julia Gillard, who flew to Tasmania on Monday, warned that New South Wales, Australia's most populous state, was about to move into a period of extreme heat Tuesday when the wildfire risk would be high.

"We live in a country that is hot and dry and where we sustain very destructive fire periodically," Gillard told reporters. "Whilst you would not put any one event down to climate change … we do know over time that as a result of climate change we are going to see more extreme weather events and conditions."

New South Wales Rural Fire Service Commissioner Shane Fitzsimmons said more than 90 wildfires were blazing across the state Monday and warned that conditions would worsen on Tuesday. No homes were currently under threat.

"It is going to be very hot and very dry. Couple that with the dryness of the vegetation, the grassland fuels, the forest fuels and those strong winds that are expected tomorrow," he said.

The temperature across much the state was expected to reach 45 degrees Celsius while winds were expected as high as 80 km/h.

Wildfires are common during the Australian summer. In February 2009, hundreds of fires across Victoria state killed 173 people and destroyed more than 2,000 homes.