(File photo: AFP)

The UN migration agency says a boat carrying dozens of migrants has capsized in the Atlantic Ocean off the West African nation of Mauritania, causing the deaths of at least 57 people.

Laura Lungarotti is head of the International Organization for Migration. She says on Twitter that more than 83 migrants from Gambia survived the shipwreck Wednesday.

Lungarotti says women and children were among the dead.

Agency spokeswoman Safa Msehli says survivors have told the UN body that the boat had left Gambia carrying some 150 migrants.