CALCUTTA, India (May 29, 2009)--Officials in India and Bangladesh say the risk of disease outbreaks is growing as hundreds of thousands of people crowd into government shelters after being flooded out of their homes by a deadly cyclone.

The death toll from Monday's cyclone stands at 264 in the two countries.

In India, West Bengal emergency officials say half a million people have been left homeless. Relief officials are using aircraft and boats to deliver food, water and medicine to people who have not made it to the government-run camps.

In Bangladesh, the government has stopped announcing the number of displaced people, but says several thousand remain in shelters.

Medical teams fear an outbreak of waterborne diseases such as diarrhea and typhoid from a lack of clean drinking water.

Officials say many village wells have been swamped by salty water, making them unfit for drinking.

Conservationists are also expressing concern for tiger populations, after their habitats of mangrove forests were inundated.