The UN refugee agency says as many as 240 people are believed drowned in two shipwrecks off the coast of Libya.
The agency's spokeswoman in Italy, Carlotta Sami, said 31 survivors of two shipwrecks who arrived on November 3 on the Italian island of Lampedusa reported that their boats capsized in heavy seas.
Sami said the survivors reported that a total of about 240 people were missing in the wrecks.
Most of the people onboard the two ships appeared to have been sub-Saharan Africans.
More than 4,200 migrants have died making the dangerous journey across the Mediterranean Sea this year, according to the International Organization of Migration.
Over the first 10 months of the year, nearly 155,000 migrants have reached Italy, most of them from sub-Saharan Africa.