A small boat floats down the Niger River near where a boat carrying hundreds of people capsized in the Mali section of the Niger River Saturday. Ben Curtis/AP

A boat carrying hundreds of passengers along the Niger River in central Mali has capsized, and nearly 200 people remain unaccounted for hours later, the mayor of a nearby town said Saturday.

Konna Mayor Sory Diakite told The Associated Press that 20 bodies had been recovered by midday. At least 400 passengers were believed to have been onboard the vessel, though only 210 survivors had been counted, he said.

Crews were still searching the river for bodies late Saturday afternoon, said Ibrahim Maiga, who heads Radio Korondougou in Konna.

Family members in the capital of Bamako said they had received confirmation of the accident as well.

"The boat sank around 8 p.m. between Mopti and Konna," said Abouri Djittey, a resident of Bamako. "It was a survivor who called me around 9 p.m. to tell me that my pregnant daughter and her friend had both drowned."

The boat was traveling to the northern town of Timbuktu when it capsized Friday about seven kilometers (4 miles) from Konna, Diakite said.

"For the moment, the conditions of what exactly happened are not known," he said.

Large boats carry hundreds of people on the Niger River at this time of year, and the journey can take up to two nights and two days to reach the fabled northern town of Timbuktu. Boats are often overloaded, and some carry two levels of passengers.

While most Malians cannot swim, travel by water is preferable to journeying on the poor roads across the country's desert north.

The Associated Press