Migration charities fear that more than 30 people may have drowned after their dinghy sank while trying to reach Spain’s Canary Islands in the north-east Atlantic.
The two charities said there had originally been 59 people on board but on Wednesday morning one warned the boat was taking on water.
Morocco, which administers Western Sahara, the nearest part of the African mainland, has reportedly rescued 24 people.
But the Spanish coastguard said two bodies, including a child, had been found.
Refugees and migrants often attempt the sea route to the Canaries but local sea currents are hazardous.