Dozens more migrants were feared missing, as a new major shipwreck was believed to have occurred off the coasts of Sicily, Xinhua quoted authorities as saying.
The navy confirmed it rescued 39 migrants aboard an inflatable boat about 160 km off Lampedusa, a tiny island that lies 113 km from Africa. Two of the migrants had serious burns and were picked up by an emergency helicopter in order to receive medical care most quickly.
Ten people were found dead, the navy added.
Another man was found alone on a similar craft by a trading ship 190 km off Pelagie islands, closer to the Libyan coasts.
According to migrants' accounts, the first boat capsized Friday due to bad sea conditions when they were some 65 km off Libya, and dozens among them would not have survived.
Migrants told authorities some 80-90 people at least went missing during the storm, the media reported. Nothing more specific was discovered about the second craft, but both navy and coast guard kept searching the waters for other possible missing.
"The situation is very serious, patrol boats are finding several corpses and survivals told they were around 500 aboard. I hope it is not so," Lampedusa mayor Giusi Nicolini told state TV broadcaster RAI News 24 during operations Saturday.
Survivals were brought on a bigger navy vessel that was already carrying other people rescued the previous days. The ship was expected to reach Palermo port in Sicily Sunday with 700 migrants aboard, the navy said.
The sea patrols were part of a major operation called Mare Nostrum (Our Sea), which Italy launched in October 2013 in order to tackle an increasing wave of migrants and try to save those who undertake the perilous journey from Africa to Europe.
Mare Nostrum was set up after more than 400 migrants died in two major shipwrecks off Lampedusa, and it was backed by the European Union (EU). Since then, however, the inflow coming especially from Libyan coasts has not receded and the government appealed for more EU help in terms of funds and common strategy.