DHAKA: An overloaded ferry carrying up to 200 passengers sank Monday on a river in central Bangladesh, police said.
Rescue teams have pulled around 100 people out of the water, authorities said. Two dead bodies have been found, but the rest remain unaccounted for.
The boat was around 30 kilometres (20 miles) south of the capital Dhaka when it sank in rough conditions.
"We have heard that the ferry was overloaded with passengers and the river was rough," local police chief Tofazzal Hossain told AFP.
The police chief of Madaripur, where the ferry began its journey, said it was carrying between 170 and 200 passengers.
But one survivor, speaking on local television, said he the ferry was overloaded with up to 350 passengers.
"There was no storm, but the weather was cloudy and the river was rough. The waves were huge," he said.
"Suddenly the ferry was hit by a wave and flooded with water. I got out through a window and the ferry sank quickly.
"I was rescued by a local motor boat, other people were also rescued by boats."
Bangladeshi ferries do not maintain passenger logbooks, and are often overloaded.
Ferry accidents are common in the impoverished country, with overcrowding and poor ship design and maintenance often to blame.
Emergency workers at the scene said thousands of onlookers had gathered on the banks of the swollen river Padma, in the district of Munshiganj, where the boat sank.
August is monsoon season in Bangladesh, when rivers run high, and the ship was completely submerged.
"Our divers are going to locate the sunken ferry and start the rescue operations," Mohammad Dulal of the fire service told AFP.
Bangladesh, one of Asia's poorest nations, is criss-crossed by more than 230 rivers and boats are the main form of travel, especially in the southern and northeastern regions.
However many of the vessels in use date back to before independence in 1971.
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.
In May, a passenger ferry thought to be carrying between 150 and 200 people sank in central Bangladesh, killing dozens of people. The exact death toll remains unknown.
Survivors blamed the ship's captain for refusing to take shelter from a gathering storm.
Around 150 people were killed in the same district in March 2012 after an overcrowded ferry carrying about 200 passengers sank when it was hit by an oil barge in the middle of the night. (AFP)