NOUAKCHOTT, Mauritania — Scores of migrants who swam through rough Atlantic Ocean waters to safety from a capsized boat were receiving care Thursday in Mauritania after 58 others drowned in one of the deadliest disasters this year among people making the perilous journey to Europe.

The boat that left Gambia a week ago had been carrying at least 150 people, including women and children. It was headed toward Spain’s Canary Islands but tried to approach the Mauritanian coast to get fuel and food, Laura Lungarotti, chief of mission in the West African nation with the U.N. migration agency, told The Associated Press.

“Many drowned. The ones who survived swam up to the Mauritanian coast close to the city of Nouadhibou,” she said. The survivors were recovering from shock, she said, adding that they were given first aid kits, blankets and other supplies.

Local authorities searched for an unknown number of missing people.

At least 83 people swam to shore, including two women and at least 10 minors, the UN agency said. Mauritanian authorities said they found at least 85 survivors, 10 of whom were taken to the hospital for “urgent” treatment.