The bodies of some 150 illegal migrants have been found off the coast of Tunisia after the capsize of a boat bound for Europe.
An recsue operation began off the Kerkennah islands on Wednesday.
According to the Tap news agency, 570 people were rescued, but up to 270 were missing.
The migrants - mostly from West Africa, Pakistan and Bangladesh - were on a boat bound from Libya for Italy. They had sailed from Tripoli on Saturday.
Italy has seen an influx of refugees since the fall of the regime of Zine al-Abidine Ben Ali in Tunisia in January and the outbreak of war in Libya. Most arrive on the island of Lampedusa.