16 survivors and at least 50 deaths have been reported so far by the International Organization for Migration in the incident.
Bodies of three migrants were found on Friday, a spokesman for the Tunisian defense ministry said, adding the boat left Zwara, on the northwestern Libyan coast, on Thursday.
Interior ministry spokesman Sofiene Zaag said however around 75 people are believed to have been on board the Italy-bound boat when it departed Libya.
These latest deaths bring to 493 the total for 2019 to date, with 307 reported on the Central Mediterranean route between Libya and Italy. This compares with 620 deaths confirmed during the same period in 2018, including 383 deaths on the Libya-Italy route. (ILKHA)