The Italian Navy says at least 40 people have been found dead on board a barge carrying migrants off the coast of Libya.
Italian media has reported that dozens of migrants suffocated in a hold underneath the deck of a boat.
Hundreds of other migrants have been rescued and taken on board Italian naval vessel the Cigala Fulgosi.
The latest incident comes less than two weeks after around 200 people died when the wooden boat they were in capsized in the Mediterranean.
The Irish naval vessel LÉ Niamh brought around 360 migrants ashore in Palermo following that tragedy.
More than 2,000 people fleeing poverty and war have died attempting to cross the Mediterranean to Europe this year.
