Cities and villages in south and western India found themselves under water on Wednesday after monsoon rains lashed the country, forcing hundreds of thousands of people from their homes.
India's annual drenching, which is crucial for the 600 million people who live off the land, caused reservoirs to overflow and rivers to swell in five states.
The result was floods that have killed almost 200 people in the last eight days and submerged fields, villages and towns.
The rising waters forced the closure of a natural gas plant and petrochemical factories in the western city of Hazira in Gujarat.
Low-lying areas of Mumbai, India's commercial capital, were also under water. The death toll in Maharashtra, the state of which Mumbai is the capital, topped 60, with 105,000 people displaced.
In Goa the state government sounded flood alerts in areas close to its dams.
The worst-hit state appears to be Andhra Pradesh, where more than a million people have been evacuated and housed in temporary relief camps across the state.
Hundreds of villages are still cut off and army helicopters were used to drop food and water to survivors.
In Gujarat, scores of villages and the industrial town of Surat, known for its diamond-cutting and textile industries, went without power as floodwaters inundated the region. More than 200,000 people were evacuated.
Military boats and helicopters were deployed to rescue thousands clinging to trees and rooftops.
Sixty per cent of Surat city was submerged and nearly 3.5 million people living in and around the town were affected by the floods, the Press Trust of India news agency reported.
The situation was expected to worsen as the administration had released water from Ukai dam, which was threatening to overflow.
Experts say that in many places bad dam management has compounded the monsoon's effects. Himanshu Thakkar of the South Asia Network on Dams, River and People pointed out that Surat had not experienced a particularly heavy monsoon this year.
"The area has seen about 1.2m of rain since June 1, which is 12 percent more than expected. [The monsoon] is not why there is flooding," he said.
Thakkar said the real problem was the Ukai dam, which was already more than a fifth full before the rains began.
"That meant there was no flood cushion when the monsoon came and the release of water flooded the city. It is sheer inept management that caused this flood," he said.
The president of India's ruling Congress party, Sonia Gandhi, and the home minister, Shivraj Patil, flew over affected areas in Andhra Pradesh on Wednesday.
Yesterday Indian Prime Minister, Manmohan Singh, will visit flood survivors.