Four migrants dead, 21 missing off coast of Spain
Rescuers saved the three people from the sinking boat late Thursday, and appealed for other vessels to look out for the missing migrants, a coast guard spokeswoman said.
One body was recovered from the boat while the other three were found floating nearby, she added.
The vessel was first spotted around 70 kilometres (40 miles) west of Spain's Cape Trafalgar by a passing merchant ship which sounded the alarm.
Two men were found alive on board the boat while a woman was rescued from the water.
The survivors said the boat had departed for Spain with 28 people on board.
A helicopter was dispatched in the search for the missing migrants, which began on Thursday night.
Spain is one of the largest gateways for migrants departing from North Africa and seeking a better life in Europe.
Migrant boats are tempted in part by the narrowness of the Strait of Gibraltar, a 13-kilometre-wide waterway that separates Europe and Africa, despite strong currents that sink many boats.
More than 27,000 migrants have arrived by sea in continental Spain and the Balearic and Canary Islands between January and the end of September, a 54 percent increase over the same time in 2020, according interior ministry figures.
The International Organization for Migration says at least 1,025 migrants have died trying to reach Spain in 2021, making it the "deadliest year" on the migratory route.
The route to Spain's Canary Islands in the Atlantic off the coast of Morocco is especially dangerous.
According to Caminando Fronteras, a Spanish NGO that monitors SOS calls from migrants at sea, more than 2,000 people have died or gone missing trying to reach the Canaries in 2021.