17 found dead off Canary Islands

Seventeen people were found dead on a boat drifting off El Hierro in Spain's Canary Islands, officials said, as migrant arrivals to the archipelago 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 on Monday 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.

At its shortest, the sea crossing to the Atlantic islands from the Moroccan coast is around 100 kilometres, but it is a notoriously dangerous route because of strong currents. Vessels are also typically overcrowded and in poor condition.

Migrant arrivals on the archipelago surged after increased patrols along Europe's southern coast dramatically reduced crossings to the continent via the Mediterranean.