The bodies of 17 migrants were brought ashore in Sicily aboard an Italian naval vessel yesterday along with 454 survivors as efforts intensified to rescue people fleeing war and poverty in Africa and the Middle East.
More than 5,000 migrants trying to reach Europe have been saved from boats in distress in the Mediterranean since Friday and operations are in progress to rescue 500 more.
In some of the most intense traffic of the year, migrants who left Libya in 25 boats were picked up by ships from Ireland, Germany, Denmark, Italy, Britain, Malta and Belgium, assisted by planes from Iceland and Finland, the EU's border control agency Frontex said.
The 17 bodies found on one of the boats arrived in the Sicilian port of Augusta aboard the Italian navy corvette Fenice. Italian prosecutors are investigating how they died.
Frontex is co-ordinating an EU rescue mission known as Triton, which was stepped up after around 800 migrants drowned off Libya in April in the Mediterranean's most deadly shipwreck in living memory.
"This is the biggest wave of migrants we have seen in 2015," Frontex executive director Fabrice Leggeri said. "The new vessels that joined operation Triton this week have already saved hundreds of people."
Italy has so far borne the brunt of rescue operations. Most of the migrants depart from the coast of Libya, which has descended into anarchy since Western powers backed a 2011 revolt that ousted leader Muammar Gaddafi.
Calm seas are increasingly favouring departures as warm weather sets in.