The boat, carrying as many as 400 Italy-bound North Africans, capsized some 185 km south of Lampedusa island, Italy’s southern most point, Xinhua reported.
Around 215 people were rescued.
“We do not know yet how many people were on board, but survivors say there were hundreds,” Lampedusa port captain Giuseppe Cannarile said.
“We are on the spot and are working tirelessly,” he said.
Last week, as many as 1,000 asylum seekers landed in Sicily, the latest arrivals adding to more than 25,000 migrants who had reached Italy in the first few months of this year. Most of the migrants are reportedly from sub-Saharan Africa, with an increasing number from Syria and the Palestinian territories.
The unsustainable overcrowded conditions in Italy’s migrant centres have repeatedly been exposed.
Italy’s interior ministry had estimated earlier this month that some 800,000 North Africans were poised to set off for Europe.
Italian authorities have said that sea operations are insufficient to prevent more fatalities and have called for the creation of a “humanitarian corridor” and greater support for rescue and resettlement efforts from the EU.
Rescue operations for sea patrol missions cost the Italian government more than nine million euros ($ 12.3 million) every month.