Swollen rivers swamped thousands of villages and towns across India's south and west on Wednesday, forcing 4.5 million from their homes as rescuers struggled to bring them food and drinking water, officials said.
India's annual monsoon rains - vital for the country's agriculture-driven economy - have triggered floods across at least five states since the weekend, killing at least 311 people, submerging villages and causing widespread damage to crops.
Most deaths were reported from the western state of Maharashtra, where 163 people have been killed in four days of incessant rains, 86 of them in the past 48 hours, officials said.
Floods had forced more than 200,000 people out of their homes in nearly 3,500 villages of Maharashtra, a relief official said. In Maharashtra and also neighbouring Gujarat, military boats and helicopters continued to reach out to thousands who remained marooned on trees and rooftops, many without food and water, after rivers burst their banks and flooded homes.
In Gujarat, about 200 villages were cut off and the industrial town of Surat, known for its diamond-cutting and textile trades, went without power as floodwaters inundated the region, leaving around three million people homeless.
Indian television channels said 90 percent of the town was submerged and showed pictures of people wading through waist-high water and vehicles almost totally submerged.
In the southern state of Andhra Pradesh, where 112 people have perished in four days of rain, some 6,000 villages have been flooded, leaving around 1.5 million homeless and forcing thousands into trees and onto rooftops.