The head of Tunisia's Red Crescent says the bodies of dozens of migrants who drowned trying to reach Europe from Libya will take days to surface.

Mongi Slim told The Associated Press Saturday that around 75 migrants left the Libyan city Zouara aboard a boat that capsized Friday. Of those, Mongi said, only 16 survived after being rescued by a Tunisian fishing boat. He said the 14 Bangladeshis, a Moroccan and an Egyptian are receiving care from the U.N. refugee agency in Medenine, a southern Tunisian city.

Slim estimated that around 55 bodies are still unaccounted-for — nationals of Bangladesh, Egypt, Morocco and unspecified countries in sub-Saharan Africa.

The International Organization for Migration called it the deadliest migrant boat sinking since January.