Flood waters were starting to recede in the north of the country but would not subside in central areas for at least two or three weeks, the official news agency BSS said quoting meteorological experts.

The process would take even longer if, as forecast, the situation was aggravated by further monsoon rains, they said.

The flooding which at one point submerged two-thirds of Bangladesh was now affecting about half the country, with the death toll now at 452, the agency said.

Meanwhile, in Dhaka, where tens of thousands of flood victims were growing increasingly desperate for food and clean water, BSS said new areas had been inundated, leaving nearly two-thirds of the city under water.

The water has been contaminated by the collapse of the sewerage system putting public health at risk and increasing pressure on hospitals, the agency added.

Officials told AFP the waters were highly contaminated because in order to limit the flood water entering Dhaka, some water gates had been closed, stopping sewage flowing out of the city.

Water board workers in Dhaka were distributing supplies of drinking water to flood hit people in Dhaka, BSS said Thursday, although many flood victims told AFP they had not yet received any.

"We came to this shelter but we have not received anything," Rashid Bepair, 65, told AFP.

Another man, Sanwar Ali, 38, said most people were getting by on water taken from open tanks at mosques normally used by worshippers to wash before prayers.

Rivers close to Dhaka continued to flow far above danger levels and troops were asked to repair breaches to the earth embankments built alongside them.

The government and international relief organisations said Wednesday that millions across the country were without adequate supplies of food and fresh water.

The World Food Programme, which has started distributing rice and water purification tablets to flood victims in the north and centre of the country, has said Bangladesh "could face a major humanitarian crisis" over coming days.

The flooding is the heaviest since Bangladesh's worst floods yet of 1998 that left more than 700 people dead and 21 million homeless.

The government has said it welcomed international aid and expected to make an appeal for assistance with post-flood rehabilitation.

The United States and Britain have already announced aid donations and the United Nations is to launch an appeal to bolster the ongoing relief work.

Low-lying Bangladesh which is criss-crossed by a network of 230 rivers suffers annual flooding caused by monsoon rains and melting ice from the Himalayas.

Since July 10, the flooding has also claimed hundreds of lives across other parts of south Asia including northeastern India and Nepal.

TERRA.WIRE