A ferry with about 200 passengers on board has capsized in Bangladesh in a river southwest of the capital, Dhaka.

About 100 people are unaccounted for, the chief of the district administration said.             

Low-lying Bangladesh, with extensive inland waterways and slack safety standards, has an appalling record of ferry accidents, with casualties sometimes running into the hundreds.

Overcrowding is a common factor in many of the accidents and each time there is an accident the government promises to toughen regulations.

The deputy commissioner of Munshiganj district said about 100 passengers had been rescued from the vessel after it went down in the Padma river.

Two women had been taken to hospital and died and the remainder of those on board were unaccounted for, he said.

There was a possibility some had swum to the riverbank.

"Most of the passengers were coming back to the city after celebrating Eid al-Fitr," the commissioner said, referring to the festival marking the end of the Ramadan.

Teams from the Inland Water Transport Authority, fire brigade and the army were helping with the rescue about 30km southwest of Dhaka.

The stretch of river where the ferry sank was deep and the weather was bad meaning there was no sign of the boat under the choppy water.

In March 2012, 145 people died when a ferry sank near the same spot.