Hundreds of African migrants were feared drowned in the Mediterranean Sea on March 23 after a charity's rescue boat found five corpses close to two sinking rubber dinghies off the coast of Libya.
The UN's refugee agency said it was "deeply alarmed" after the Golfo Azzuro, a boat operated by Proactiva Open Arms, reported the recovery of the bodies close to the drifting, partially-submerged dinghies.
Proactiva spokeswoman Laura Lanuza said the inflatables are like those usually used by people traffickers, and would typically have been carrying 120-140 migrants each.
Lanuza said the bodies recovered were African males aged between 16 and 25, all recently drowned.
Despite rough winter seas, migrant departures from Libya on boats chartered by people traffickers have accelerated in recent months from record levels.
Nearly 6,000 people have been picked up by Italian-coordinated rescue boats since the end of last week, bringing the number brought to Italy since the start of 2017 to nearly 22,000. That is a significant rise over previous years.
The International Organization for Migration has recorded 559 deaths in the Mediterranean so far this year. About 5,000 were recorded during 2016.