The U.N. refugee agency says 57 Somalis drowned when their boat capsized Sunday in rough waters in the Gulf of Aden near southeast Yemen.
The agency reported Thursday that 54 of those who died were refugees and three were smugglers.
It said the only survivor swam nearly a full day before reaching the Yemeni coast near the town of Bir Ali.
The agency said 23 bodies had been recovered as of late Wednesday.
The head of the U.N. refugee agency, Antonio Guterres, said he and his colleagues are "horrified by this latest tragedy." He said the Gulf of Aden remains one of the deadliest routes for those fleeing conflicts, violence and human rights abuses in the Horn of Africa.
The agency said the drowning marked the largest loss of life in waters between Somalia and Yemen in one incident since January 2008, when 114 people drowned after a boat capsized.
It said 89 people have drowned or disappeared this year in waters between Somalia and Yemen.