East of Hobart, the state capital, as many as 2,000 people have taken refuge in the town of Nubeena, while another 700 sheltered at the nearby historic Port Arthur site. Others have been ferried to emergency accommodation in Hobart.
One of the worst affected areas was the small community of Dunalley, about 55km east of Hobart, where police estimate about 30 percent of buildings have been destroyed, including the police station and school.
In nearby Connelly's Marsh, about 40 percent of buildings have been ruined.
Prime Minister Julia Gillard said it was a "tragic time for those who have suffered loss in the devastating Tasmanian bushfires" and that the government would help support those affected.
Bushfires are also burning in other parts of Australia, including South Australia, Victoria, New South Wales and Queensland.
Bushfires 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.
Wildfires on the Australian island of Tasmania have stranded thousands of people and destroyed at least 100 homes.
Much of Australia is experiencing a heatwave, and temperatures in the Tasmanian state capital Hobart earlier reached a record high of 41C.
Some took shelter on beaches on the Tasman Peninsula, which remains cut off.
The main road to the Tasman Peninsula, south-east of Hobart, has been cut off, stranding thousands of people, many of them tourists in the historic site of Port Arthur.
