Most fatalities in the industrial powerhouse state were in the coastal districts of Raigad and Ratnagiri, where several villages were cut off after heavy monsoon rains.
Maharashtra's relief secretary, Krishna Vatsa, said the government had called in the army, navy and air force to assist thousands of people who were stranded and to pull out possible survivors of landslides.
"We have not been able to reach some villages where more than several dozen people may be missing in landslides," Vatsa told Reuters, confirming at least 30 deaths in Raigad and Ratnagiri and adding that electricity, telephone links and transport connections had been cut off to those districts.
Press Trust of India reported 54 fatalities in Raigad district alone due to floods and landslides. In coastal Maharashtra, officials and media reported more than 1,700 people had been rescued since Tuesday.
Trading on Bombay's bond and currency markets was cancelled and Maharashtra Chief Minister Vilasrao Deskmukh declared a state holiday saying conditions were very bad. The government asked people to stay at home as further heavy rains were forecast.
"The situation is so grave (that despite) these human efforts, we are not in a position to reach out to the people who are in the districts," Deskmukh told NDTV television.
Late on Tuesday, another official said that in the village of Juigao, about 150 km (95 miles) south of Bombay, 150 villagers were feared buried after a landslide.
In Bombay -- home to the Bollywood movie industry -- and its suburbs, thousands of office workers had to stay overnight in hotels, and schools were shut on Wednesday as rain continued overnight, flooding roads and stalling hundreds of cars.
NDTV reported that people were trapped in a double-decker bus overnight due to flooding and some children were unable to reach home after school ended on Tuesday.
Flights from Bombay airport, India's busiest, were suspended, leading to rising anger among stranded passengers.
Many suburban trains in the teeming city of more than 15 million people remained disrupted on Wednesday.
"We are appealing to people to stay indoors and as it expected to rain heavily today so the situation is not expected to ease," Vatsa said.
Flooding in the monsoon season in India, which runs from June to September, kills hundreds of people each year and disrupts life in wide swathes of land. (Additional reporting by Thomas Kutty Abraham)
- Reuters - Thomson Reuters Foundation
- For more humanitarian news and analysis, please visit https://www.trust.org/alertnet