The lighter vessel was carrying 2000 tonnes of wheat when it sank in rough sea near Hatiya, about 40 nautical miles away from Patenga sea beach of Bangladesh.
The Coast Guard and Navy are conducting the search operations. The Public Relations Division of Coast Guard said that their team failed to reach the spot due to strong current in the area.
Another vessel carrying Sugar reportedly sank near Bhashanchar around the same time on Saturday but its crew members were rescued.
A lighter vessel carries cargo from the larger mother vessel moored at the outer anchor of the port.