NEW DELHI - Health workers disinfected wells and distributed chlorine tablets to thousands of villagers rushing back to their homes as water levels receded sharply in northern India, officials said Wednesday.

Many defied warnings to remain in relief camps to ensure it was safe to return to their flood-hit homes, said L. B. Prasad, the Uttar Pradesh state director-general of health services.

More than two weeks of monsoon rains across much of northern India, Bangladesh and Nepal have flooded rivers and inundated plains, killing at least 443 people and stranding some 19 million more, officials said.

Villagers have been given chlorine tablets to purify drinking water and were advised to take precautions for the next few days, Prasad told The Associated Press in Lucknow, the capital of Uttar Pradesh.

International aid groups have warned of an impending health crisis if help does not reach millions of South Asians stranded by heavy flooding, amid forecasts of more rain in the devastated region.

With weather clearing this week, aid workers, government officials and the military have rushed food, drinking water and medicines to flood-hit areas.

Flood victims face a shortage of drinking water in Bihar, said R. K. Singh, the state's relief coordinator. Authorities stopped air dropping water pouches after complaints that they broke upon landing, Singh said.

Water will be supplied in plastic bottles and other containers, along with packets of flour, salt, candles and matches, he said.

The disaster's scale has dwarfed relief efforts.

Stagnant waters left by the floods are a lethal breeding ground for diarrhea and waterborne diseases at an epidemic level, he said.

Babille said people are also at risk from skin infections, malaria, leptospirosis and dengue fever.

More than 1,000 people in Uttar Pradesh state are sick, mainly from cholera and gastroenteritis, officials said.

In Bangladesh, there were 1,400 reported cases of diarrhea this week, 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.

At least 251 have died in India since last week because of the monsoon floods. Another 192 people have died in Bangladesh, mostly from drowning in swirling floodwaters, waterborne diseases like diarrhea, snake bites or electrocution from contact with submerged electric wires, the Information Ministry said.

Since Tuesday, 25 bodies have been recovered in India's eastern Bihar state and 14 in northern Uttar Pradesh state, officials said. Another 28 deaths were reported Wednesday from Bangladesh's 38 affected districts, the ministry said.

Since the start of the monsoon in June, the government says more than 1,200 people have died in India alone.