Australia's flood disaster has continued to worsen, with at least four people left dead in the city of Toowoomba after a torrent of water swept cars and pedestrians into churning rapids.
Flash floods have deluged the nation's already sodden northeast, swelling rivers to fresh peaks and submerging roads and bridges.
Anna Bligh, the Queensland premier, said: "Mother Nature has unleashed something shocking on the Toowoomba region.
"This is without a doubt our darkest hour of the last fortnight."
Queensland police said four people, including two children, had died but that a number of others were possibly still missing in the surging brown waters which have swamped an area the size of France and Germany.
'Freak of nature'
Bligh described the waters as "a freak of nature", saying they had hit communities with "lightning speed" and left at least six people missing.
"We believe we're looking for at least three young pedestrians and two vehicles that seem to have been washed away," she said.
Footage showed vehicles flipped and tossed into trees in Toowoomba, a city of about 90,000 people, when the sudden torrent swept through.
"A wall of water came down, picked my ute [utility vehicle] up, pushed it sidewards," said Steve Jones, Lockyer Valley mayor, likening the damage to a cyclone or atomic bomb.
"If it had been a little car it would have killed everyone in it."
Bligh said authorities held grave fears for the safety of a number of people in the nearby Grantham township.
"We are unable to reach some 30 people in the town of Grantham," she said.
"They have all gathered together in a primary school at Grantham. They are completely isolated by fast moving flood waters."
Miltary search
Bligh said the military would begin searching for stranded people at first light while police issued warnings that residents of low-lying areas of other towns including Chinchilla should evacuate to higher ground.
Julia Gillard, the prime minister, said 150 regions across three Australian states had been hit by the deluge since November.
More than 8,000 claims for emergency assistance had been made, worth $10m, and many more were expected.
But the damage bill would take some time to process, Gillard warned, with the flooding's end not yet in sight and many road, rail and bridge assets still under water.
The deluge has wiped out crops and brought dozens of coal mines to a standstill, driving up world prices and causing problems for the key steel-making industry.
The disaster, which has now claimed more than a dozen lives, is expected to shave at least $6bn from Australia's economy.
