More than 80 migrants were saved, but two died and three were missing following two sea rescue operations in the Mediterranean off the coast of Libya, the Doctors Without Borders (MSF) charity said on Sunday.
MSF's vessel Geo Barents picked up over 60 people late on Saturday from a rubber dinghy in distress in international waters off Libya. It also recovered one body, and one of the migrants taken on board died shortly after the rescue.
Another 19 people were picked up from a nearby abandoned Tunisian offshore oil platform, MSF said. The migrants told rescuers they swam there after the boat they were travelling on started taking in water.
Three people remained on the boat and were now missing, the charity added.
Mediterranean sea crossings from North Africa to Italy or Malta are among the world's most dangerous migration routes. Last year almost 2,500 migrants died or went missing on those routes, according to the International Organization for Migration.
"All the survivors are now recovering and cared for on the Geo Barents after these traumatic ordeals," MSF said, adding it had asked for permission for them to disembark at "the closest place of safety possible."
Charity vessels normally take rescued migrants to Italy, and the country's right-wing government often assigns them to disembarkation ports that are far away, requiring several days of navigation to reach them.
Reporting by Alvise Armellini