Rescuers brought more than 350 migrants to shore in Sicily on Wednesday, along with the bodies of five women and two men who had died on the perilous journey.
More than half had been taken from three boats in distress off Libya's coast on Monday, staff from the Malta-based Migrant Offshore Aid Station (MOAS) said.
They were taken onto the rescue vessel Responder, along with 171 people transferred from other ships in the area, said the MOAS officials who worked with the Red Cross.
Responder reached the Sicilian port of Augusta two days later.
Italy's coastguard said a total of 2,700 boat migrants and 15 bodies were found off the coast of Libya on Monday, in another day of mass departures from north Africa.