Italian authorities have recovered 24 bodies from the waters south of Sicily where a migrant boat capsized, as the official Vatican newspaper compared a series of disastrous incidents involving would-be refugees fleeing northern Africa for Europe to a war.

The Italian navy said that two of its patrol boats managed to pull 364 people alive from the water, after a fishing boat used by human smugglers overturned en route from Libya to Italy on Sunday night.

Rescue teams initially said six migrants had drowned, but later found more bodies. Their remains, as well as the survivors, were being carried to the city of Augusta on Sicily's east coast, the navy said.

It was the third such incident to be reported by Italy's search and rescue services in two days.

Up to 170 migrants were feared dead after a boat sunk off the Libyan coast on Saturday, while a few hours later 18 died as an inflatable dinghy sunk south of Italy's southernmost island of Lampedusa.

Italian authorities said they rescued almost 4,000 migrants altogether over the weekend, adding to the more than 100,000 who have reached the Mediterranean country so far this year.

Fuelled by the increasing instability in Libya, where human smugglers operate, migrants' arrivals have exceeded the previous yearly record of 62,000 set in 2011 during the Arab Spring uprisings. Hundreds have died in the perilous crossing.

In an article headlined: 'Like a war', the Holy See newspaper L'Osservatore Romano described the situation as an "endless massacre".

"A new silent war is being fought in the Mediterranean. That of immigration," the paper wrote.

Interior Minister Angelino Alfano has renewed calls for the European Union to help Italy's search and rescue operations. He is due to discuss the issue at a meeting with EU Commissioner for Home Affairs Cecilia Malmstroem later this week.