Media playback is unsupported on your device Media caption The BBC's Nick Bryant reports on rooftop rescues across Queensland

The Australian state of Queensland is facing a "major flood crisis", its premier has warned.

Rescuers are trying to reach hundreds of people stranded in the city of Bundaberg by rising waters and there are fears homes could be washed away by fast-moving waters.

Three people have already died in the Queensland flooding, after a cyclone brought heavy rain.

Australian PM Julia Gillard offered her condolences to the families of victims.

Ms Gillard was speaking in Gipsland, Victoria, where she was visiting people afflicted by the recent wildfires.

Do not wait. Move now. Yr life depends on it Ian Stewart on Twitter, Queensland police commissioner

She said it had been a "tough period" for Queensland, and that the whole country was being "challenged by nature".

"But we are a strong and smart nation and we'll get through this, as we always do, by pulling together," she said.

Hospital evacuation

Floods in late 2010 and early 2011 left 35 people dead across Queensland, with Bundaberg among the towns affected.

In 2010, the Burnett River at Bundaberg reached 7.92 metres, but at 15:00 (05:00 GMT) on Monday, the river was at 9.2m and rising slowly, the Bureau of Meteorology (BoM) said in a statement.

It is expected to peak late on Tuesday or early Wednesday. Major flooding has also been reported at Mundubbera and Gayndah, said the BoM.

State premier Cambell Newman said it was "a major flood crisis for the people of Queensland".

"However they're up to the challenge. We will get through this. There is a team there working hard, state and local government, to protect them, to rescue them, to make sure that in the days and weeks to come we clean up and put it all back together."

Image caption There are fears fast-moving waters could wash away homes in Bundaberg

Mr Newman said the north of the city had been split into several islands and that rescue workers were trying to reach hundreds of people still trapped.

He said 14 helicopters had been plucking people from rooftops but that more were being brought in, and some would work throughout the evening. He urged stranded people to group together and ensure less mobile people were not left behind.

Preparation were also being made to evacuate more than 100 people from the city's hospital, he said.

The authorities were "very concerned about what may happen this evening".

Residents had earlier been ordered to evacuate immediately, with the state's Police Commissioner Ian Stewart tweeting: "Do not wait. Move now. Yr life depends on it."

Police Superintendent Rowan Bond said many people had only a few hours left in which to leave, before becoming stranded, saying there was an "imminent danger of people being killed and drowned".

By late afternoon, the main Bundaberg evacuation centre at Oakwood State School was itself evacuated, the Brisbane Times reports. Some 300 people were being moved to another centre near the airport.

Elsewhere in the state, some 350 homes have been flooded in Ipswich. More than 200,00 people are without power across the state. Residents of the Lockyer Valley, which was the scene of deadly flash floods in 2011, have also been told to evacuate as creeks and rivers rise.

The town of Gympie has been cut off and dozens of businesses are underwater, ABC News reports, while hundreds of homes are threatened in Ipswich, where the Bremer River is expected to peak later in the day.

Police said the body of an elderly man who went to check on a yacht north of Bundaberg had been recovered on Sunday. Two men swept away by flooding in separate incidents in Queensland were also found dead on Monday.

In Brisbane, which was paralysed by flooding two years ago, water has been creeping into low-lying parts of the central business district.

A woman and her three-year-old son were also taken to hospital in Brisbane after a tree fell on them.

The rain was brought by Tropical Cyclone Oswald, which is now affecting the northern part of New South Wales.

The BoM has warned of heavy rain, usually high tides and damaging winds, with gusts of up to 100 km/h (62 mph). Flash flood warnings have also been given.

A number of roads have been closed in the state and 6,000 homes are without power in the north.