As of May 30, 32,080 people reached Europe by sea this year, while 660 died attempting the crossing.

The rescue operation was ongoing, the defence ministry said on Sunday.

“The coastguard and the navy continue their search with the support of a military plane,” the interior ministry said in a statement.

The International Organisation for Migration (IOM) said there were more than 70 survivors from the shipwreck, with spokesman Flavio Di Giacomo cautioning on Twitter the final number of missing was still uncertain.

“There were around 180 of us on board the boat … which sank because of a leak,” a survivor told Tunisia’s Mosaique FM radio, describing the boat as nine metres long.

Another rescued person said the captain abandoned the vessel after it started sinking to escape arrest by the coastguard.

“I survived by clinging to wood for nine hours,” he said at a hospital in the southern city of Sfax, where dozens of people gathered to look for survivors and identify dead relatives.

The latest shipwreck is the most deadly in the Mediterranean Sea since February 2 when 90 people drowned off the coast of Libya, according to IOM.

Human traffickers increasingly use Tunisia as a launch pad for migrants heading to Europe as Libya’s coastguard, aided by armed groups, has tightened controls.

Security officials said the boat was packed with about 180 migrants, including 80 from other African countries.

Unemployed Tunisians and other Africans often try to depart in makeshift boats from Tunisia to Sicily in Italy.

Separately, nine people including six children died on Sunday after a speedboat carrying 15 refugees sank off the coast of Turkey‘s southern province of Antalya, the Turkish coastguard said in a statement.

As of May 30, 32,080 people had reached Europe by sea so far this year, IOM said on its website. Some 660 had died attempting the crossing.