At least nine bodies were recovered after three to four boats capsized in stormy conditions during a race on the Sabang river in Assam state of India.
The boats were caught in a sudden rainstorm on Sunday in the town of Tikkri Killa in the remote northeast state, police officer Mukesh Sahay said.
Rescuers were searching for several people missing in the accident about 255 (155 miles) west of Gauhati, Assam state's capital, reports AP.
Sahay said it was not clear whether the dead were all participants in the rowing boat race because some people were travelling on the same river stretch in motor boats when the accident happened.
Boating accidents in India are common.
Many ferries are poorly built and overcrowded. There is little regard for safety regulations and life jackets.