At least four persons, including a woman drowned, and more than 50 others were missing after a boat capsized in the Ganga River in West Bengal's Malda district at 7.45am on Friday.
While around 15 people managed to swim ashore, the rest are missing.
Locals said the boat was overloaded, and strong winds caused turbulence in the river. The passengers, mostly farmers, were crossing to the other side for work. Early reports said women were also on board along with some cattle.
This is a wide stretch of the Ganga before the river branches off into Bangladesh.
The accident took place at Manikchak, around 400km to the north of Kolkata. The spot does not have adequate infrastructure to start immediate rescue work. It is feared many may have drowned.