“There were at least 50 people on board … Our rescue divers are still searching,” coastguard spokesman commander Hayet Ibne Siddique said.

The ferry – which departed from central Munshiganj district – sank as it was about to moor at Sadarghat, Dhaka’s main river port used by hundreds of boats to travel to the country’s south.

Bangladesh Inland Water Transport Authority’s chief, Commodore Golam Sadeqk, said the single-deck ship was “not overcrowded” and sank “due to carelessness”.

He said the vessel had been cleared to carry passengers until September.

Witnesses told local television stations many passengers appeared to be stuck in the ferry’s cabins.

Divers were still pulling bodies from the wreck, in waters some 40-50 feet (12-15 metres) deep. The deceased were put in body-bags before they were laid in rows at the harbourfront.

Another boat would later arrive to lift the damaged vessel from the water, Siddique said.

Relatives gathered at Sadarghat despite coronavirus social distancing concerns to search for their family.

“I still don’t know what happened to them,” a man, searching for his cousin and another relative, told reporters.

Boat accidents are common in Bangladesh, which is criss-crossed by more than 230 rivers.

The South Asian nation is heavily reliant on ferries for transport but has had a poor safety record.

Experts blame badly maintained vessels, lax safety standards at shipyards and overcrowding for many of the accidents.

In February 2015 at least 78 people died when an overcrowded ship collided with a cargo boat in a central Bangladesh river.

The number of accidents has dropped sharply in recent years as authorities crackdown on unseaworthy vessels.