Around 250 people are missing in the Mediterranean sea after a boat taking migrants illegally from North Africa to Europe got into difficulties.
The boat capsized during the rescue operation. Around 570 of the migrants were rescued, the rest fell into the sea and are presumed dead.
The fishing vessel broke down just off the coast of Tunisa, near the port of Sfax. The victims are thought to be mainly from Somalia, Nigeria, Bangladesh, the Ivory Coast, Chad and Sudan.
A Tunisian official said two boats had been sent to rescue those on board. They saved as many people as they could, he added.
It is thought the boat could have been trying to get to Italy. Thousands of people fleeing the upheavals in North Africa have crossed the sea on small boats in their desperation to escape the violence.