Almost 1,300 migrants arrived in Sicily on rescue ships over the weekend after crossing the Mediterranean, while a 16-year-old boy died on one of the ships, Italy's Coast Guard said.
Italy has seen migrants arriving by boat at a record-setting pace so far this year, with far more people braving the crossing from North Africa this year than in the previous three years, Italian figures showed on Friday.
Another 500 migrants were heading to Sicily and expected to arrive in the next couple of days, after being picked up from flimsy boats off the coast of Libya.
Proactive Open Arms, which operated one of the rescue ships, also said on Twitter that five migrants had drowned before one of the rescues, but a Coast Guard spokesman could not confirm the deaths.
In Catania, on Sicily's east coast, the body of the 16-year-old boy was taken off the Siem Pilot, a Norwegian vessel operating on behalf of European Union border agency Frontex.
"Unfortunately one of the migrants ... died on the Siem Pilot on Friday morning as a result of an illness," the ship's commander, Jorgen Berg, told Reuters. The boy's illness was still unknown, but he had no visible wounds, Berg said. His nationality was not disclosed.
There had been 487 migrant deaths in the Mediterranean as of March 2, according to International Organization for Migration, higher than the 425 during the first two months of last year.
Boat migrant arrivals in Italy are up more than 57 percent on the same period last year, according to Italian Interior Ministry figures. About half a million have arrived in Italy since the start of 2014, with a record 181,000 arriving in 2016.
Those who have come so far this year have told of increasing violence and brutality in Libya, where rival factions battle for power and people smugglers operate with impunity amid the chaos left by the 2011 overthrow of longtime ruler Muammar Gaddafi.
Humanitarian groups say an agreement signed last month between Italy, the EU and the U.N.-backed government in Tripoli is one of the causes for the recent surge in migrant departures.
The agreement aims to stop more migrants for setting out for Europe in part by funding migrant camps in run by the U.N.-backed government.