ROME – At least 94 people have died after a boat carrying African migrants sank off the southern Italian island of Lampedusa, the island's mayor says.
More than 150 have been rescued but about 200 are missing, officials say.
Passengers reportedly threw themselves into the sea as the vessel got into trouble and Italian officials were quoted as saying that dozens of people were still in the water.
Most of those on board were from Eritrea and Somalia, said the UNHCR.
The boat was believed to have sailed from Libya, the Italian coast guard said.
Earlier this week, 13 migrants drowned while trying to reach Sicily.
In the latest incident, Simona Moscarelli, a spokeswoman from the International Organization for Migration in Rome, told the BBC that "at one point there was a fire on the boat and so the migrants moved, all of them, to one side of the boat which capsized".
She estimated that only three of about 100 women on board survived, adding that most of the migrants were unable to swim. "Only the strongest survived," she told the Associated Press news agency.
It is one of the worst such disasters to occur off the Italian coast in recent years; Prime Minister Enrico Letta tweeted that it was "an immense tragedy".
The boat was believed to have been carrying about 500 people at the time.
"There is no miraculous solution to the migrant exodus issue," said Italian Foreign Minister Emma Bonino. "If there were we would have found it and put it into action."
Also on Thursday, local media reported that around 200 migrants were escorted to the port of Syracuse on the island of Sicily, when the vessel encountered difficulties five miles off the coast.
Footage from the scene showed bodies being laid out on Lampedusa's dockside.
The mayor of Lampedusa, Giusi Nicolini, described the scene as a "continuous horror".