At least 74 migrants died in a "devastating" shipwreck on Thursday off the Libyan coast, the United Nations said, the latest in a spate of migrant vessel sinkings in the central Mediterranean.
This year has seen a resurgence of boats in the central Mediterranean, a well-trodden but often deadly route for those hoping to travel to Europe, mainly embarking from Libya and neighbouring Tunisia.
The UN's International Organization for Migration reported "a devastating shipwreck which claimed the lives of at least 74 migrants today off the coast of Khoms," in a statement, adding that the coastguard and fishermen were searching for survivors.
The IOM called it the latest disaster in a "series of tragedies" involving at least eight other shipwrecks in the Mediterranean sea since the start of October.
"The boat was reported to be carrying over 120 people, among them women and children," the IOM said, adding that 47 survivors had been brought back to shore and 31 bodies retrieved.
The IOM said that in the past two days, at least 19 other people, including two children, drowned after two boats capsized in the central Mediterranean.
More than 20,000 migrants have died in the last seven years, according to the UN refugee agency.
Human traffickers have taken advantage of persistent violence in Libya since the 2011 fall of dictator Moamer Kadhafi, turning the country into a key corridor for migrants fleeing war and poverty in desperate bids to reach Europe.
While many have drowned at sea, thousands have been intercepted by the Libyan coast guard, which has been backed by Italy and the EU, and returned to Libya.
They mostly end up in detention, often in horrific conditions.
Rights groups have denounced the policy, and the IOM has campaigned to end returns to the North African country, 300 kilometres (185 miles) from the Italian coast.
"The mounting loss of life in the Mediterranean is a manifestation of the inability of states to take decisive action to redeploy much-needed, dedicated search and rescue capacity in the deadliest sea-crossing in the world," said Federico Soda, the IOM's Libya mission chief.
"We have long called for a change in the evidently unworkable approach to Libya and the Mediterranean, including ending returns to the country and establishing a clear disembarkation mechanism followed by solidarity from other states.
The latest shipwreck comes as Libyans were hammering out Thursday in Tunisia the powers of a proposed transitional government in UN-led talks aimed at ending a brutal decade-old conflict.
Since Kadhafi's ouster and killing, oil-rich Libya has been gripped by chaos and violence, with rival administrations in the east and the west vying for control of the country.
The political talks in Tunisia follow a ceasefire deal struck in October, and come as military talks, also led by the UN, were underway in Sirte, Kadhafi's hometown.
The IOM said that so far this year, at least 900 people had drowned in the Mediterranean trying to reach European shores -- some due to delays in rescue.
More than 11,000 others have been returned to Libya, it said, "putting them at risk of facing human rights violations, detention, abuse, trafficking and exploitation".
The IOM said it had recorded a recent upsurge in departures from Libya, with some 1,900 being intercepted and returned, and more than 780 arrivals in Italy from Libya since the start of October.
The humanitarian ship Open Arms rescued around 100 migrants on Wednesday when their boat capsized, killing five people aboard, the charity that operates it said.
The humanitarian vessel is the only one operating in the Mediterranean right now, with others run by non-governmental groups held for various reasons in Italian ports.
