At least 10 people were killed and many more trapped when a state transport bus plunged into the Purna river in Maharashtra's Buldana district on Wednesday, police said.
The bus was on a regular Shegaon-Paturda service carrying around 45 passengers, including several school students, a police officer said.
Around 11 a.m., the bus was on the Khiroda bridge when it suddenly plunged into the swirling waters below.
The cause of the accident was not immediately known.
Local villagers managed to rescue at least 20 people. Rescue and relief operations were continuing.
Buldana, famous for its crater created by a meteorite hit, the Lonar Lake, is situated around 550km east of Mumbai.