Spanish authorities said Sunday that they had recovered the bodies of four migrants from a boat along with 19 survivors who had taken the treacherous route from West Africa to the Canary Islands.

Spain’s maritime rescue service said that its crews had responded to an alarm call by a fishing boat that had located the migrants in a flimsy craft unfit for the high seas. Rescue helicopters airlifted groups of the migrants to Tenerife, including six people who were in poor health and suffering from dehydration.

The Atlantic crossing from the Western coast of Africa to Spain’s Canary Islands has become a major route for migrants and asylum-seekers fleeing conflict, violence and economic plight exacerbated by the coronavirus pandemic. More than 2,400 people have reached the Canaries in the first three months of this year.

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Last year, 23,000 people arrived by boat to the archipelago and nearly 850 others have died or gone missing along the way, according to the U.N. migration agency’s Missing Migrants Project.

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