SYDNEY: A man was missing in raging floodwaters and hundreds of homes were evacuated in northeastern Australia as storms pelted the Queensland state on Sunday, with the army put on standby as the weather worsened.

Towns and cities devastated by floods in Queensland two years ago which claimed 35 lives were bracing for another devastating inundation as ex-tropical cyclone Oswald hammered the northern state.

A 27-year-old man was missing after he attempted to cross a swollen creek near Gympie north of Brisbane and a swift-water rescue team lost their boat trying to retrieve him, according to the town's mayor Ron Dyne.

Dyne said a number of people had been forced to retreat to the roofs of their homes to await rescue from the rising waters, with the centre of Gympie expected to flood later Sunday.

“At this stage, we've got major concerns,” said Dyne. “Everything's occurred rather rapidly given the amount of rain we've had.”

Further north, major flooding was expected in the towns of Bundaberg and Gladstone, with hundreds of homes and businesses at risk, some of which had only just been rebuilt following the 2011 floods.

An emergency evacuation warning was issued in Bundaberg after the Burnett River broke its banks on Sunday afternoon. It was expected to peak at more than nine metres, well in excess of the devastating 7.92m seen in 2011.

In Biloela, west of Bundaberg, a woman had to be plucked to safety after spending eight hours clinging to the branches of a tree.

The Insurance Council of Australia declared a state wide catastrophe, noting there had already been “severe inundation...in several towns and cities” and that major flood warnings had been issued.

“Unfortunately, this catastrophe declaration is the result of the first cyclone to come close to the coast this season, and the weather bureau has warned it's highly possible we will see more before the end of summer,” said ICA chief Rob Whelan.

At least one international flight was diverted from Brisbane to Sydney due to the high winds and Qantas has cancelled a number of domestic services, with the Sunshine Coast regional airport shut down.

About 900 homes had been evacuated in the Gladstone region and about 100 backpackers were sheltering in a community centre at Rainbow Beach after being removed from Fraser Island according to Dyne.

Queensland Premier Campbell Newman said the army was on standby to assist in the unfolding emergency.

“The challenge now is that we've got multiple events going on,” Newman told reporters, adding that he had spoken with Prime Minister Julia Gillard.

The weather bureau said there had been reports of “possible tornado activity” throughout southeastern Queensland overnight and warned that further storms were likely, bringing “significant damage or destruction to homes and property”.

Cyclones and floods are common in Australia's northeast during the warmer summer months. A massive inundation of Queensland in 2011 killed 35 people and brought Brisbane to a standstill for several days, swamping some 30,000 homes.