The UN refugee agency says up to 500 people are feared dead in a shipwreck in the Mediterranean Sea last week.
UNHCR said the disaster occurred between Italy and Libya, according to dozens of survivors who were rescued on April 16 by a merchant ship.
The survivors said they had been among 100 to 200 people who left a town near Tobruk, Libya, on a smugglers' boat last week.
The agency said in a statement on April 20 that "after sailing for several hours, the smugglers in charge of the boat attempted to transfer the passengers to a larger ship carrying hundreds of people in terribly overcrowded conditions."
The agency said "at one point during the transfer, the larger boat capsized and sank."
The 41 survivors -- 37 men, three women, and a 3-year-old child -- were rescued by a merchant ship and taken to Kalamata, in Greece.
Those rescued include 23 Somalis, 11 Ethiopians, six Egyptians, and a Sudanese national.
Based on reporting by AP and dpa