Prime Minister Phan Van Khai said the floods could last several more weeks and he called on the delta authorities to give top priority to saving lives and providing relief, the official Vietnam News daily reported.

Disaster officials said 164 children were among the dead.

The United Nations Children's Fund has expressed concern about the high level of child casualties and appealed for $392,000 to help set up more day care centres and to provide additional health care and clean drinking water.

Children were the biggest casualties last year when the delta's worst floods for decades killed 480 people. Many children are left unattended when parents seek help, food or work.

The disaster officials said more than 275,000 houses - home to 1.38 million people - have been inundated with flood waters in 43 districts of six Mekong Delta provinces and 187,000 families, or some 935,000 people, needed relief.

The national weather centre said waters at two key measuring points in the Delta - Tan Chau on the Tien River and Chau Doc on the Hau River - were at 4.60 metres (15 feet) and 4.35 metres (14 feet) respectively, 0.4 metre and 0.85 metre (1.3 and 3 feet) above danger levels.

The centre forecast the upstream waters on the border with Cambodia and in the delta ricefields would recede slowly in the next five days.

Many of those who were evacuated from the floods have been camped in unsanitary conditions on exposed and often crumbling earth dykes, increasing the risk of illnesses such as diarrhoea.

Damage to the agricultural crops and rice in particular have been minimal because most of the latest summer-autumn rice crop had been harvested before the floods peaked late last month.

VNA said the floods had damaged a total 4,000 hectares (9,884 acres) of rice, affected 30,000 hectares (74,130 acres) of subsidiary food crops and fruit trees. The delta grows three rice crops a year with 1.3-1.4 million hectares each crop.