At least 74 people are know known to have died and a further 120 are missing after a ferry sank overnight in Bangladesh.

The ferry got caught in a sudden tropical storm on the Buriganga river on its way to the southern town of Chandpur.

Efforts are underway to salvage the sunken vessel, where it is feared many of the missing may be trapped.

Local authorities say that the final death toll will not be known until the vessel is fully salvaged.

They say that the exact number of people on board may never be known as ferry operators do not keep passenger lists and often fill ships beyond their capacity.