Libya has called off efforts to retrieve bodies of over 200 illegal migrants who drowned when their overcrowded boat capsized in the stormy waters of the Mediterranean as they set off for a better life in Europe.

Laurence Hart, an official with the International Organization for Migration in Libya, said Wednesday that authorities stopped the rescue operation since chances were slim of finding more survivors from the weekend incident.

Only 20 survived when the wooden vessel with 257 people on board, mostly African migrants and including 70 women and two children — both of whom died — sunk only three hours off Libya.

Hart said aid workers heard survivors' accounts at the Twesha refugee center outside of Tripoli on Wednesday. "Many had kidney problems from swallowing sea water because they spent eight hours in the sea," he said.

About 21 bodies were found by Tuesday morning, and several more bodies washed ashore Tuesday night, near the ancient port city of Sebrata, some 50 miles (80 kilometers) west of Tripoli, Hart said.

Survivors of the capsized boat said that the smuggler, an Egyptian national, died, the IOM reported. The survivors said their boat left the Libyan coast early Sunday morning, said Michele Bombassei of the IOM's Tripoli office. Three hours later the boat capsized. There have been conflicting reports on when the boat went down reflecting the difficulty of obtaining information on the furtive crossings from often-traumatized survivors.

The Egyptian consulate in Tripoli said at least 10 Egyptians traveling on the capsized boat died, according to a report in the Egyptian state news agency, MENA.

Libya has not released any official figures in what is believed to be the deadliest migrant ship accident between North Africa and Europe in recent memory.

Thousands of African, Asian and Middle Eastern migrants fleeing wars and poverty use Libya and other North African countries as launching pads for the dangerous journey across the Mediterranean to southern Europe — often in rickety, overloaded boats.

Hundreds are believed to die in the journey each year. The route between Libya to an island off the coast of southern Italy is one of the most heavily traveled for illegal migrants trying to reach Europe.

Another flimsy vessel with about 350 migrants, including women and children, was rescued in the same area where the fishing boat capsized after the boat managed to send out a distress signal. The survivors of the capsized boat were discovered by Libyan authorities responding to the distress signal, Bombassei said.

There were also unconfirmed reports of two more migrant boats that had managed to reach the shores of Italy and Malta, Hart said.

U.N. refugee agency's William Spindler said from Geneva that a UNHCR team talked to the migrants rescued from that second vessel, which drifted for 13 hours until it was found by Libyan coastal guards close to an oil field.

Those migrants were now at the al-Zawia camp outside Tripoli, Spindler said.

The UNCHR was told by 19 Syrian Kurds from the group how they paid $2,000 per person to be smuggled to Italy. They arrived by plane from Syria two months ago, landing at the Tripoli airport and were taken by smugglers to a place near Tripoli until their departure, Spindler said. And 35 Somalis recounted how they reached Libya by land from Somalia, he added.

Italy has been pressing Libya to crack down on illegal immigration, including deploying joint Libyan-Italian patrols in the Mediterranean. Rome says many of the illegal African immigrants who arrive in Italy transit through Libya.