Scores of people are missing after a ferry carrying about 100 passengers sank in a river in Bangladesh, officials say.

Police on Friday said there were no immediate reports of casualties after the ferry, MV Sarosh, collided with a barge laden with sand and went down on the River Meghna in Munshiganj district, 32km south of the capital, Dhaka.

"So far we have gathered that the ferry was carrying around 100 people and some have swum to the banks," local police chief Jahangir Hossain told AFP news agency.

The private television station Channel-I said local villagers rescued more than 40 people after the accident.

District administrator Saifuddin Badal, however, said that more than 50 people were still unaccounted for.

"We heard around 25 people have swum ashore," he said.

Badal said the boat was carrying passengers from Dhaka to the southeastern district of Chandpur.

"The rescue vessel MV Rustam has arrived at the scene. We expect we can salvage the ship very soon," he said, adding that divers had been called in to help locate the boat.

Lax safety standards

The exact number of people on board was uncertain as passenger lists are often not maintained properly in Bangladesh and many travellers buy tickets on board.

Officials said the vessel was not overloaded.

Hundreds of distraught relatives gathered on both sides of the river, anxiously waiting to know the fate of their family members.

Bangladesh, a delta nation of 153 million people, has a history of boating disasters as a result of lax safety standards and frequent overloading of vessels.

Last March, more than 100 people were killed after a passenger vessel sank in the Meghna river after colliding with a cargo ship.

Ferries are the main form of transport in Bangladesh, a low-lying country that is subject to frequent flooding and where the road network is rudimentary.

However many of the vessels that plough the 230 or so rivers that traverse the country date back to before independence in 1971 and overcrowding is frequent.

Naval officials have said more than 95 percent of Bangladesh's hundreds of  thousands of small and medium-sized boats do not meet minimum safety regulations.

Source: Agencies