As many as 80 African migrants, mostly Ethiopians, were feared drowned after two boats capsized off the coast of south Yemen, the interior ministry said on Monday.
"The accident was caused by high winds and a tsunami which capsized the two boats taking them towards the coast," it said in a statement, quoting the coast guard in the southern port city of Aden.
One boat with 46 migrants, most of them Ethiopians, "capsized in a coastal region ... of Taez province, with all those on board drowning except for three Somalis who survived", it said.
Another boat carrying "between 35 to 40 people, all of the Ethiopians and among them women and children" went down off the coast of another southern province, Lahij, the ministry said.
"Their fate is not yet known," it said, adding that a search was underway but without specifying what day the incidents took place.
Each year tens of thousands of Ethiopians and Somalis make the perilous crossing to Yemen in the hope of escaping the economic deprivation, persecution and conflicts of their home countries.
Many die on board often overcrowded and rotten small boats, while others, already weakened by long journeys from the hinterland to the coast, die at the hands of ruthless smugglers.
The migrants generally slip by boat into the south of Yemen, itself one of the world's poorest countries, before heading towards the border with oil-rich Saudi Arabia.
The United Nations High Commissioner for Refugees said last April that the exodus of Somalis across the Gulf of Aden had slowed dramatically since the start of 2010, despite recurring violence in Somalia.