At least 113 people have died off of the coast of the island of Lampedusa, Italy after their ship caught fire and sank, spilling hundreds of passengers into the sea.
The ship was carrying approximately 500 people, of whom 140 have been rescued. Most of the remaining hundreds are missing, officials say.
It has been called one of the deadliest such accidents in recent times in the notoriously perilous crossing from Africa for migrants seeking a new life in the European Union.
"The immense tragedy at Lampedusa... is unbearable for any human being," Italian Transport Minister Maurizio Lupi said, according to Reuters.
The mayor of Lampedusa, Giusi Nicolini, described the scene as a "continuous horror".
Pope Francis sent a Twitter message calling for his followers to pray for the victims of the tragic shipwreck off Lampedusa. In July he visited the island and condemned the "global indifference" to the plight of migrants trying to arrive there.
At this time of year, when the Mediterranean tends to be calmer, ships carrying migrants from Africa and the Middle East land on Italy's southern shores almost every day, but often the vessels are overcrowded and are not seaworthy.
On Wednesday a draft report from human rights body the Council of Europe said that Italy was "ill-prepared for a new surge of mixed migration on its coasts".
Italy's system for receiving and processing migrants and asylum seekers was not fit for purpose, a council committee on immigration said.