Lack of clean drinking water and the collapse of sewage systems had led to the outbreak of water-borne diseases in flood-affected districts, BSS said, although it did not elaborate.

It said the death toll from the floods had risen from 185 to 202 while the number of people affected rose from 19 million to 30 million, out of a population of 140 million.

Flood Warning Centre officials quoted by BSS said the floods would continue to spread through parts of the capital Dhaka Saturday.

The situation in central and northwestern parts of the country would also continue to deteriorate, the officials said.

Low-lying Bangladesh, criss-crossed by 230 rivers including major arteries carrying melting snow from the Himalayas, suffers annual flooding during the monsoon affecting at least 20 percent of the country.

Aid agencies and health officials say stagnant, polluted water can cause a range of water-borne diseases including diarrhoea, dysentery, typhoid and cholera.

The flooding is the most serious since Bangladesh's worst ever floods of 1998 which killed more than 700 people, left 21 million homeless and submerged two-thirds of the country.

TERRA.WIRE