More than 60 African migrants have drowned while crossing the Gulf of Aden on their way to Yemen.

Witnesses say at least 15 others swam to safety after their vessel sank close to the Yemeni coast. The boat originated from Somalia and most of those on board are believed to have been Somalians.

It is not clear how the boat capsized.

Migrants frequently attempt the crossing to escape violence in Somalia and often rely on smugglers to help them cross.

They often face abuse at the hands of smugglers, with many forced to disembark offshore to avoid Yemeni coast guard patrols.

Earlier this month, the U.N. High Commissioner for Refugees estimated 20,000 people have made the crossing this year and said at least 439 people have died and another 489 are missing.

Some information for this report was provided by AP and Reuters.