Ten bodies were fished out of the Niger River in Nigeria's northern Kebbi state on Wednesday after an overloaded boat with about 100 passengers broke in two, a local official said.
The dilapidated vessel was crossing the river and broke in two as it approached the village of Samanaji in Koko-Besse district.
It had taken on passengers "way beyond its capacity," said Yahaya Bello Koko, a district official.
"We found 10 passengers with the help of local divers, and we are still looking for 10 more," he said.
They "are presumed drowned, considering the number of hours they spent in the river," Koko said.
More than 80 passengers were rescued, he said.
Federal or state authorities were not immediately available.
Accidents involving boats are common in Nigeria. They are often linked to overloaded vessels, excessive speed, poor maintenance and disregard for navigation rules.
In October, at least 80 people drowned in two shipwrecks.
Gabon arrests 33 after ferry disaster
Gabon: More than 21 bodies recovered from deadly shipwreck
Go to video
Madagascar: death toll rises to 34 in shipwreck near Mayotte
Malawi declares state-of-disaster after cyclone's deadly return
Death toll in Gabon ferry disaster rises to 6 with 31 still missing
Go to video
30 migrants missing after shipwreck off Libya