Police in Bangladesh say a boat carrying an estimated 100 people sank in calm waters off the coast.
No survivors were found by nightfall, but one body was recovered.
Police say the boat may have been operated by human traffickers. They say it's unlikely that any survivors of the sinking will come forward and report to authorities if they had been trying to migrate illegally.
A local police chief says the wooden fishing boat went down near Saint Martin's island, about 75 miles south of the coastal resort town of Cox's Bazar.
The passengers' nationalities were not immediately known, but police say they could be Bangladeshis or refugees from neighboring Myanmar.