At least 35 people died when two trawlers collided head on and capsized in the river Dhanu in the northeastern Sunamganj district on Saturday night, the local administration said.
At least 20 passengers remained missing till 1:00am, the police said.
Both the trawlers capsized after the collision.
Jamalganj upazila nirbahi officer Abul Hashem told New Age that the locals had recovered 35 bodies of women and children floating in the river in the remote Alipur area in the upazila.
Quoting witnesses, the district administration officials said that a trawler from Bholaganj of Sylhet, headed for Etna of Kishoreganj carrying about 70 passengers, had smashed head on with a sand-laden trawler at about 8:00pm in the river under Jamalganj upazila.
Some 15 passengers swam ashore, while the locals recovered the 35 bodies floating in the river, the police said.
Sunamganj police superintendent Golam Kibria said told New Age that the death toll could rise.
The police said that the accident had taken place due to poor visibility in dense fog. Cold and fog made rescue operation difficult.
The Fire Service and Civil Defense sent its three divers to the spot to join the rescue operation.
Some of the deceased were identified as Rafiqul, 8, Nima Begum, 7, Husna, 32, Sabbir, 7, Akash, 12, Taslim, 12, Kakon, 10, Tawhida, 8, Shithi, 6, Mithi, 1, and Anufa, 28.
Unauthorised motorboats meet frequent accidents claiming many lives, said the Bangladesh Inland Water Transport Authority officials.
According to the BIWTA, a total of 396 accidents took place from 1977 to June 2010 killing about 4,047 people. Some 341 went missing in ferry accidents during the period.
At least 80,000 unlicensed boats operate on river routes taking advantage of lax monitoring.
The government does not have any survey of waterway vessels except the registered 12,000 vessels.
Representatives of Bangla-desh Inland Waterways (Passenger Carriers) Associa-tion said motorised boats operated even on the mighty rivers without safety measures.
A parliamentary panel asked the shipping ministry 17 months ago to develop a mechanism to throw all unlicensed boats out of the inland river routes.