DAKAR: Forty-seven migrants are feared to have died off the coast of Mauritania after a boat was found drifting with seven survivors on board, an official with the UN's migration agency said Tuesday.

The boat left the Laayoune region of Western Sahara on August 3, heading for the Spanish archipelago of the Canaries, but suffered an engine failure and drifted for nearly two weeks before being spotted by Mauritanian coastguards on Monday off Nouadhibou, Nicolas Hochart of the International Office for Migration (IOM) told AFP.