LIBYA | MIGRANTS | DETAINED 

Around 5,000 migrants are being held in official detention centres in Libya, and they represent just the tip of the iceberg, the chief of the International Organization for Migration said Wednesday.

"It remains very unacceptable in terms of the violation of the rights of migrants in the country." "We have always made it clear that detention is not a solution," IOM director general Antonio Vitorino said during a press briefing organized by the United Nations in Geneva. 

Under the UN, the IOM collaborates with the refugee agency UNHCR to provide life-saving assistance to migrants in official detention centres.

"But we fear that there are non-official detention centres about which neither agency has any knowledge or access," Vitorino said.

Libya became a preferred route for tens of thousands of migrants from Sub-Saharan Africa, the Middle East, and South Asia seeking to reach Europe after the fall of Moamer Kadhafi's regime in 2011.

When migrants attempting the life-threatening journey across the Mediterranean are intercepted by authorities, some are brought back to the Libyan coast and placed in detention centres. They are regularly denounced by the UN for poor conditions.

Vitorino called on the European Union to show "clarity" and "predictability" when it comes to search and rescue operations in the Mediterranean, particularly on the safety of disembarkation points.

Italy's geographic location has made it the destination of choice for asylum seekers from North Africa, but a new law introduced in January has limited humanitarian ships to carry out only one rescue at a time.

Vitorino said his agency met the Italian officials last week "precisely to address the situation" but offered no further details about the discussion.