The death toll is likely to rise because more than a dozen others were reported missing in the accident near Buxar, a town in Bihar state, said Neelmani, the state director-general of police.
Neelmani, who uses one name, said at least 25 people were able to swim ashore. The region is about 100 miles (160 kilometers) west of Patna, the state capital.
He said 22 bodies were recovered from the river and divers were searching for others.
The accident occurred as the poor farm workers were returning home after working in nearby villages.
Monsoon rains have swelled the river in recent days.
Boat accidents are common in India, where many vessels are unsafe and overloaded.
