The International Organization for Migration (IOM) announced on Monday that 64 migrants drowned after their flimsy boat sank off the Libyan coast this week.
Flavio Di Giacomo of IOM said in tweet Monday that survivors interviewed by the agency in Catania said 150 people had been aboard the dinghy when it set out from a Libyan beach east of Tripoli.
"Sixty-four migrants lost their life in the shipwreck (which) occurred last Saturday," Di Giacomo said, saying "probably 56 missing migrants" perished at sea.
In a telephone interview with The Associated Press, Di Giacomo said the dinghy was packed and made of poor quality rubber.
Eighty six people were plucked from the stricken rubber dinghy on Saturday and eight bodies, all women, were recovered. However, the boat had been carrying 150 migrants, survivors said, with many of the dead vanishing beneath the waves.
The Italian coastguard said the migrants had been spotted on Saturday morning by a plane patrolling the seas on behalf of a European anti-smuggling operation. Rescuers believe their dinghy deflated following a puncture.
The IOM estimated that 2,832 migrants died last year trying to reach Italy from North Africa, down from 4,581 in 2016. Some 119,310 people made it alive to Italy in 2017 against 181,436 the year before.