The accident occurred as the boat was crossing the Godavari River in Andhra Pradesh state, police superintendent Madhava Chary told AFP from West Godavari district, 500 kilometres from the state capital Hyderabad.
About 50 passengers were on the boat which capsised early in the morning and had the capacity to carry 35 passengers, police said.
"We have retrieved 12 bodies so far, including five women and four children. Another 20 to 25 people are still missing," Chary said, adding some of the passengers were able to swim to safety.
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