The bodies of seven migrants, including a small boy, were found during the latest rescue operations off Libya, a Maltese NGO and the Italian coastguard said.
"Imagine to carry an eight-year-old boy's lifeless body into your house on Easter Sunday. I will never forget this day," tweeted Chris Catrambone, founder of Maltese NGO Moas.
Dozens of Mediterranean rescue operations throughout the day spotted around 2,000 would-be migrants, according to an Italian coastguard estimate.
As weather conditions deteriorated, NGOs urged more vessels to head to the region, with their own already crammed with around 4,500 people picked up from unseaworthy vessels the previous day in 35 operations.
The fine weather going into the weekend had evidently sparked a spike in the number of people attempting the perilous crossing to Europe.
Friday had already seen some 2,000 people rescued while the body of one young man was found, presumed asphyxiated, aboard one vessel bursting with people.
With arrivals showing no sign of abating, EU's border control agency Frontex has accused donor-funded vessels of doing more harm than good by acting "like taxis" off Libya.
Italian prosecutors have suggested they may have links with traffickers — a charge fiercely rejected.
Distressing images of African migrants being plucked from heaving seas or the coffin-strewn aftermath of major sinkings have become a regular feature of television news bulletins since the crisis began spiralling out of control four years ago.
The International Organization of Migration says 666 people have been logged as dead or missing off the Libyan coast so far this year out of an estimated 27,000 who have tried to reach Italy from Libya.
Last year saw around 5,000 deaths.