Surging river waters have so far affected 17 million people in the eastern state of Bihar, officials say.
The death toll from monsoon floods in eastern India has reached 514, officials said on Tuesday.
Surging water from rivers has inundated several districts across the eastern Bihar state.
The floods have so far affected more than 17 million people. Rescue workers are scrambling to provide aid to those stranded.
''The number of affected districts is 29. In these 29 districts there are 187 blocks, 2,371 village councils and a population of approximately 17.1 million has been affected. According to figures of yesterday (August 28), 514 people have been killed in the floods,'' Dinesh Chandra Yadav, Bihar’s disaster management minister, said.
Floods hit Mumbai
Heavy monsoon rains also brought India's financial capital to a grinding halt on Tuesday, with authorities struggling to evacuate people before a high tide was expected to add to the chaos.
Incessant rain flooded low-lying areas of Mumbai and paralysed train services used by hundreds of thousands of commuters daily, with many stranded at stations.
Poor visibility has forced airport authorities to divert some flights.
Thousands waded through waist-deep water to reach home after the megacity received more than 100 mm (4 inches) of rainfall.
Children were sent home early from school. Weather officials are predicting more heavy rains over the next 24 hours and have urged people to stay indoors.
A high tide is expected to hit the city later on Tuesday.
The National Disaster Response Force launched a rescue mission with police to evacuate people from low-lying areas.
"The heavy rains, flooding, are delaying our rescue work. Even we are stranded," said Amitesh Kumar, joint commissioner of police.
Rainwater flooded the King Edward Memorial Hospital in central Mumbai, forcing doctors to vacate the paediatric ward.
"We are worried about infections ... the rain water is circulating rubbish that is now entering parts of the emergency ward," said Ashutosh Desai, a doctor in the 1,800-bed hospital.
Although Mumbai is trying to build itself into a global financial centre, parts of the city struggle to cope during annual monsoon rains.
Floods in 2005 killed more than 500 people in the city. The majority of deaths occurred in shanty town slums, which are home to more than half of Mumbai’s population.