International aid groups warned Tuesday of an impending health crisis if help does not reach millions of people in South Asia stranded by heavy flooding amid forecasts of more rain in the devastated region. More than two weeks of teeming monsoon rains across much of northern India, Bangladesh and Nepal flooded rivers, inundating plains and killing at least 376 people and stranding some 19 million more. During a brief respite in the rain, aid workers, government officials and the military have scrambled to provide food, clean drinking water and medicines in a bid to ward of an epidemic of waterborne diseases. But the scale of the disaster has dwarfed relief efforts. "Entire villages are days away from a health crisis if people are not reached in the coming days," Marzio Babille, UNICEF's health chief in India, said in a statement. "Many of the affected areas are home to poor communities who suffer from poor sanitation and hygiene year round. Stagnant waters left by the floods are a lethal breeding ground for diarrhoeal and waterborne disease at potential epidemic level," he said. Babille said people were also at risk from skin infections, malaria, leptospirosis and dengue fever. Children, who make up 40 percent of South Asia's population, are particularly susceptible. In India, officials said the problem was exasperated by contaminated wells. As the floodwaters receded, special medical camps were distributing chlorine tablets for purifying drinking water. "Health officials have also been asked to disinfect the wells," said L.B. Prasad, director-general of health in the Uttar Pradesh state. More than 1,000 people in the state were reported to be sick, mainly from cholera and gastroenteritis, officials said. In Bangladesh, there had been 1,400 reported cases of diarrheal diseases in the past 24 hours, said Fadela Chaib, a spokeswoman for the Word Health Organization. The World Food Program and UNICEF have been distributing emergency food supplies to thousands of people in Bangladesh and Nepal, said WFP spokesman Simon Pluess in Geneva. No aid was being distributed in India, because no requests for help had been received, he said. On Tuesday, eight more people died in the latest flooding, bringing Bangladesh's toll to 164, the Information Ministry said. The Flood Forecasting and Warning Center said flooding had eased in worst-hit northern and eastern areas, but swollen rivers flowing south to the Bay of Bengal threatened to flood new areas in central Bangladesh, including the region around the capital, Dhaka. Floods have submerged vast areas of cropland and damaging thousands of kilometers (miles) of roads and mud embankments in the populous, impoverished delta nation of more than 150 million people. Since the start of the monsoon in June, the government says more than 1,200 people have died in India alone, with scores of others killed in Bangladesh and neighboring Nepal, where floods have hit low-lying southern parts of the country. The respite in rains appeared to be temporary. Omar Baddour of the World Meteorological Organization said the forecast for the region for the next 48 hours was for more rain.