CAIRO — At least two people have died and 186 others were missing after four boats carrying migrants from Africa capsized overnight in waters off Yemen and Djibouti, the United Nations migration agency said on Friday.

Two vessels capsized off Yemen late Thursday, said Tamim Eleian, a spokesman for the International Organization for Migration. Two crew members were rescued, but 181 migrants and five Yemeni crew members remain missing, he said.

Two other boats capsized off the tiny African nation of Djibouti around the same time, he said. Two bodies of migrants were recovered, and all others onboard were rescued.

Strong winds caused the two boats to capsize near the beach in Djibouti after they started sailing off, said Abdusattor Esoev, the head of the mission for the I.O.M. in Yemen.

The third boat, which capsized off Dhubab district in Taiz governorate, in southwestern Yemen, was carrying 31 Ethiopian migrants and three Yemeni crew.

The fourth boat, which capsized near the same area, was heading to Ahwar district in Abyan governorate, and was carrying 150 Ethiopian migrants and four Yemeni crew.

Yemen is a major route for migrants from East Africa and the Horn of Africa seeking to reach Gulf countries for work, with hundreds of thousands trying the route each year.

To reach Yemen, migrants are taken by smugglers on often dangerous, overcrowded boats across the Red Sea or Gulf of Aden.

The numbers making it to Yemen reached 97,200 in 2023 — triple the number in 2021. Last year, the number dropped to just under 61,000, probably because of greater patrolling of the waters, according to an I.O.M. report released this month.

Over the past decade, at least 2,082 migrants have disappeared along the route, including 693 known to have drowned, according to the migration agency. Some 380,000 migrants are in Yemen.