Seventeen people were found dead on a boat drifting off El Hierro in Spain's Canary Islands, officials said, as migrant arrivals to the islands surge despite the deadly dangers of the crossing.
A Spanish military helicopter airlifted three survivors - two men and a woman - to a hospital on the island of Tenerife, local emergency services said in a tweet.
One of the men was in serious condition with "severe dehydration", it added.
A Spanish air force plane first spotted the boat some 265 nautical miles southeast of El Hierro yesterday morning and a search and rescue vessel was deployed to the area, a spokeswoman for Spain's maritime rescue service said.
The migrants on the boat were all sub-Saharan Africans, she added.
It was not immediately clear where the boat had embarked from.
Earlier this month four people were found dead in a makeshift boat that was found south of El Hierro, with 23 migrants on board.
At its shortest, the sea crossing to the Atlantic islands from the Moroccan coast is around 100km, but it is a notoriously dangerous route because of strong currents. Vessels are also typically overcrowded and in poor condition.
Migrant arrivals on the islands surged after increased patrols along Europe's southern coast dramatically reduced crossings to the continent via the Mediterranean.
Some 3,400 people arrived in the Canaries between 1 January and 31 March this year, compared with less than half that number over the same period in 2020.
Rights groups have warned that the Covid-19 crisis has spurred the flight effect, with those working in tourism, fishing or other casual jobs in north Africa choosing to cross the Atlantic - or helping others do so with their boats after being left penniless by the economic meltdown triggered by the pandemic.
Last year, 1,851 people died on the route, according to the Caminando Fronteras organisation which monitors migrant flows.
