Tens of thousands of people in Australia's southern island state of Tasmania were without power after a cold front brought damaging winds and heavy rains, sparking flood warnings.

"Around 30,000 customers are without power across the state this morning," state-owned power company Tasnetworks said.

The Australian Bureau of Meteorology said that a cold front over Tasmania, population around 570,000 people, was moving away, "although bands of showers and thunderstorms continue to pose a risk of damaging wind gusts."

Emergency authorities issued warnings for flooding, which they said could leave Tasmanians isolated for several days, as the state prepared for another cold front.

Tasmania is located 445 km from Melbourne, and about 40 percent of the island is wilderness or protected areas.