Forty-five African migrants have drowned trying to reach Europe in separate incidents on Saturday night, the Mauritanian Red Crescent says.
At least 23 people drowned in rough seas after their boat collided with a Moroccan vessel coming to its aid off the Mauritanian city of Nouadhibou.
In the second incident, another 22 drowned after their boat capsized.
Thousands of Africans risk hazardous journeys to Europe each year to escape poverty, but many die in the attempt.
The immigrants were riding in wooden canoes, a spokesman for the Mauritanian Red Crescent said. About 40 migrants were rescued.
An Italian ship was looking for another vessel carrying migrants which had put out a distress signal in Mauritanian waters, but there were no details of how many were on board, the spokesman added.
The dead migrants, who sailed from Mauritania, are thought to have come from Gambia, Guinea Bissau, Ivory Coast, Mali, Mauritania and Nigeria.