Indian air force helicopters swept low over the flooded plains of northern India today, dropping desperately needed aid to some 2 million people marooned by some of the worst flooding to hit the area in 30 years, officials said.

Water levels in several northern India rivers fell today as heavy monsoon rains eased, but the death toll across South Asia from recent floods reached 311 amid fears of an outbreak of diarrhoea and other waterborne diseases.