Ships manned by humanitarian organisations, the Italian navy and the coast guard helped rescue more than 2,000 boat migrants on Thursday as calm seas returned to the Mediterranean prompting a surge in departures.
The Topaz Responder, a ship run by the Malta-based humanitarian group Migrant Offshore Aid Station (MOAS), said 23 different migrant boats had been spotted in the sea about 20 nautical miles from the Libyan port city of Sabratha.
Rescue operations were ongoing, the Italian coast guard said. "The mass movement is probably the result of week-long, unfavourable weather conditions" that have come to an end, MOAS said on Twitter.
The Topaz Responder picked up 382 migrants from sub-Saharan Africa from three different large rubber boats. The Bourbon Argos, a ship run by humanitarian group Doctors without Borders, rescued 1,139 from 10 different boats, and two other humanitarian vessels picked up 156 more.
German humanitarian group Sea-Watch said it had taken about 100 migrants and one dead body from a rubber boat, and the Italian navy said it had rescued 515 from two dinghies.
An agreement between Turkey and the EU to stop departures for the Greek islands has reduced boat arrivals by 98 percent during the first five months of the year from the same period of 2015, the International Organization for Migration (IOM) said.
But arrivals to Italy continue at about the same clip as last year, and the deadly central Mediterranean route has already claimed 2,438 lives, IOM said.
Italy has been on the front line of Europe's worst immigration crisis since World War Two, which is in its third year. More than 320,000 boat migrants came to Italy from North Africa in 2014-15.
As of Wednesday, 56,328 boat migrants had been brought to Italy, a 5.5 percent decrease on the same period of last year, according to the Interior Ministry.
Nigerians, Eritreans and Gambians were the top three migrant nationalities this year, the ministry said, and more than 125,000 are now living in Italian shelters.
(Reporting by Darrin Zammit Lupi on the Topaz Responder migrant rescue ship, additional reporting by Stephanie Nebehay in Geneva)