"There were 116 illegal migrants in the fishing trawler. They are all Bangladeshis," coast guard station commander Dickson Chowdhury told AFP by phone.
Chowdhury said the trawler was cast adrift near Bangladesh's southern-most island of St Martin's, which is close to the border with Myanmar, after its crew abandoned it for another ship.
"It looks like a fishing trawler from Myanmar and that its crew were also from Myanmar," he said, adding the crew may have abandoned the vessel after it was chased by Bangladeshi patrol boats.
"We learnt that it was heading to Malaysia with the illegal migrants," added Al Imran of the coast guard's press department.