At least 27 people died when a boat carrying more than 200 migrants capsized in the Mediterranean.
Italian and Maltese ships - backed by helicopters - were scrambled to the scene and are searching in darkness.
Maltese PM Joseph Muscat said 203 people had so far been rescued.
The boat capsized 120km off Lampedusa, an Italian island where more than 300 African migrants drowned when their vessel went down last week.
The vessel is believed to have encountered difficulties just before sunset.