About 20 people swam to safety Tuesday evening after the ferry flipped on the Godavari River but others, including a group traveling to a wedding, remained unaccounted for.
Fishermen raced to the scene to help, and officials deployed police and a team from the National Disasters Relief Force. But the accident occurred in the late evening, and the search for survivors was slowed by poor communications and the fall of darkness.
Proper record-keeping is rare on the many ferries that work the Godavari, making it difficult to know how many people were on the boat.
Ferry disasters occur frequently in India, often because of overcrowded boats or poor maintenance. In November, a ferry capsized elsewhere in Andhra Pradesh state, leaving at least 19 people dead.
The cause of the Tuesday accident was not clear. There were no immediate reports of overcrowding and the ferry captain quickly reported to the local police station to give a statement.
