Many were feared killed as an overcrowded mechanized boat carrying nearly 200 people on Monday capsized in River Kolohi in northeast India's Assam state, said police.
The incident took place at the Kamrup district of the state, when huge crowds were rushing to see a boat race on the river on over-packed boats.
There have been no reports of anybody rescued from the boat so far, while rescue operation was going on to find any survivor, said police.
The engine of the boat, carrying the passengers from Chaygaon to Champupara villages to attend a boat race, failed to function in the middle of the river and hit against the post of a bridge, Kamrup (Rural) Deputy Commissioner Vinod Kumar Seshan told the media.
He said the passengers falling into the river "which was in spate."
Local residents and government rescuers have rushed to the spot to rescue the passengers.
Some passengers have swam to safety to the other bank of the river, according to local media.