Twenty migrants have drowned while trying to reach the Canary Islands, survivors of a boat sinking have told Spanish police.
Africans are making treacherous sea journeys to reach Europe
The survivors - seven adults and four children - said they were picked up by a merchant ship after their boat broke up on the high seas before dawn.
They said they were then brought to a port on the Gran Canaria.
Some 25,000 migrants, mostly from west Africa, have arrived in the Canary Islands this year.
Up to 3,000 people are said to have died during the trip.
Most of the migrants embark on the perilous journey in the Atlantic in open, ramshackle wooden boats.
The Canaries have become a main point of entry for illegal immigrants seeking to reach the EU, following a crackdown on migration to the north African Spanish enclaves of Ceuta and Melilla in 2005.
Spain has said it is unable to cope with the influx, describing it as a humanitarian crisis.
The EU's borders agency Frontex launched an operation in August to turn back boats carrying migrants from Senegal, Cape Verde and Mauritania to the Canary Islands.