Thirteen African would-be migrants have been found dead aboard a makeshift boat after a desperate attempt to reach the Canary Islands, Spanish officials said.
The lightly clothed migrants appear to have died of hypothermia
They appear to have died from hypothermia after a three-day journey across icy seas in bad weather.
At least three of 30 survivors are said to be in a bad condition in hospital.
Thousands of Africans try to make the treacherous journey every year, with many casualties. It is only a day since two people died in similar conditions.
The dead were found on the boat by rescuers, sent to tow it after being spotted by police.
Survivors clung to the bodies of their relatives, Spanish news reports said.
A survivor told a photographer for the news agency AFP that the passengers had been sitting in frigid water since shortly after the boat left its undisclosed African port on Monday.
The passengers were lightly dressed.
A search mission for another boat which gave out a distress call would continue on Friday, said rescuers, according to AFP.
Three children are said to be on board.
Shipping Africans to Europe is now booming business for smuggling mafias, now thought to be based largely in western Africa, correspondents say.
At least 133 people are thought to have died crossing from West and North Africa this year alone.