Devastating floods, sweeping parts of South Asia, have killed more than 700 people and affected nearly 25 million throughout the region.

The regions worst affected by the fury of the annual monsoon rains are low-lying Bangladesh and eastern India.

Officials in Bangladesh say more than half the country has been hit by flooding - the most intense in at least the last decade. Rising river waters have even submerged parts of the capital Dhaka, a city of 10 million people.

Reports from Dhaka say that thousands of people are having to take boats to get to work. Many homes have been washed away, forcing up to 100,000 people to take shelter in schools and other government buildings.

Tony Maryon, head of the Federation of Red Cross and Red Crescent Societies in Bangladesh says efforts are underway to distribute food, fresh water and medical help to millions of poor people. But, he says the situation may worsen as monsoon rains continue to lash the region over the next two months.

"When you get floods as we have in the last few weeks it shatters their lives," said Mr. Maryon. "For three months these people are going to rely on assistance. They won't be able to work until the flooding has gone down, most of them are just petty farmers, so the situation for them is very, very grim."

In India, flood waters are receding in the worst affected states of Bihar and Assam in the east.

But the situation remains worrying. Some 12 million people have been displaced, and the death toll is steadily rising as relief workers find more victims in remote areas. Most of the people have been killed by drowning, snake bites or waterborne diseases.

Transportation links have broken down in many areas and relief supplies either have to be air-dropped by helicopter or taken by boat. Officials say they are doing their best to help those affected by the floods, but there are widespread complaints of insufficient assistance.

While authorities in the east cope with flooding, the worries are very different across vast parts of northern and western India. There the monsoon rains have so far been very light and there are growing fears that farm output may be affected.

Officials say grain stocks are being increased in areas of low rainfall and measures taken to provide adequate drinking water.

The annual monsoon season in South Asia runs from June to September. It is vital for farmers, who make up more than two-thirds of this densely populated region.

But floods and landslides are also common at this time, when the rains combine with melting snows from the Himalayas to swell streams and rivers and inundate low-lying areas.