By Waliur Rahman
BBC News, Dhaka
An independent study in Bangladesh has blamed the government's "weakness" in enforcing laws as one of the major causes for repeated ferry accidents.
Scores are killed each year from ferry disasters in Bangladesh
The study by the Alliance for Safe River Routes campaign group said that ferry accidents have claimed more than 4,000 lives in the last 34 years.
Released in Dhaka on Friday, the study said some 500 ferries were involved in accidents during this period.
Ferries in Bangladesh are notorious for being overcrowded and unsafe.
The Alliance for Safe River Routes spokesman, Aminur Rasul, said more than 300 people were known to have died in the first six months of this year. Another 200 are still missing in five river ferry accidents.
Ferry accidents are common in Bangladesh, a delta nation criss-crossed by hundreds of rivers, mainly because of faulty design, overloading and poor navigation facilities.
According to the study - the most comprehensive of its kind in recent years - about 20,000 cargo and passenger vessels operate in Bangladesh, and about half of them fail to meet basic safety standards or take on more than their legal quota of passengers.
Mr Rasul said the situation is alarming, but the authorities were not doing enough to address the problems.
"On behalf of the passengers, we are urging the government to take stronger action to prevent more deaths," he said.
The study asked the government to strengthen coast guard patrols, identify dangerous river crossings, enforce registration requirements and provide training for navigators and crew.
There has been no immediate comment from the government, but ministers often claim that measures are being taken to improve safety in the waterways.