Floods described as a once-in-a-century deluge have left thousands stranded or isolated on Australia's east coast. Nearly 4,000 people may remain cut off until the weekend, and emergency crews are conducting food and supply drops.

In Queensland, heavy rains and strong winds led to flash floods, blocking roads and causing widespread blackouts. More storms have been forecast. Meanwhile, four areas have been declared disaster zones, with some 70cm (27.6in) of rain recorded in 48 hours.

Cut off

New South Wales' north coast has been "drenched by phenomenal amounts of rain", said the emergency services minister, Steve Whan, in a written statement. After visiting the region on Wednesday, Mr Whan added Clarence Valley to the list of disaster zones, which also includes Coffs Harbour, Nambucca Valley and Bellingen.

About 3,870 residents have been isolated since Tuesday night and are likely to be cut off until at least Thursday night and possibly the weekend, Mr Whan said. About 750 people spent Wednesday night in evacuation centres in affected areas. No fatalities have been reported, according to New South Wales emergency workers.

Severe weather has affected many parts of Australia in recent months. There have already been floods in the north, while in the south conditions have been extremely dry, contributing to the severity of the recent bushfires in Victoria which claimed more than 170 lives.