Sixty-four migrants are thought to have died when a rubber dinghy became punctured and sank on Saturday in the Mediterranean Sea off Libya, the International Organization for Migration (IOM) said on Monday.

The incident was 2018's first known deadly migrant shipwreck in the Mediterranean.

IOM spokesman Flavio Di Giacomo said there had been 150 people aboard the boat when it left Libya, of whom 86 survived the shipwreck. He said eight corpses had been recovered and a further 54 people were missing.

He said the information was obtained from survivors who were interviewed by the agency in Catania, Sicily, after they arrived on a rescue ship.

Initial reports had put the death toll lower, with the German migrant rescue charity Sea-Watch speaking of "at least" 25 dead.

Perilous voyage

The incident took place north of Tripoli on what is the world's most dangerous migration route. The IOM says 2,832 people drowned in 2017 attempting to cross from Libya to Europe, while 20,335 were rescued or intercepted. Altogether 118,928 people arrived in Italy via the route.

Although still high, figures have nonetheless dropped after the Italian government signed multiple deals with the Libyan coast guard in the summer with the EU's backing. 

Under the agreements, the EU and Libya cooperate in intercepting migrants as they try to cross the Mediterranean for EU shores and returning them for detention in Libya.

The cooperation has aroused controversy amid reports that migrants detained in camps in Libya have been subjected to severe mistreatment.

Read more: Tunisia's gravedigger of drowned migrants

tj/rc (dpa, AFP)