No fewer than 70 migrants reportedly drowned on Friday when their boat sank in international waters off the Tunisian coast, and 16 were saved, the state-run Tunis Afrique Presse agency said.

The boat sank 40 nautical miles off the coast of Sfax, south of the capital Tunis, it said.

However, fishing boats rescued the 16 survivors, it said.

The U.N. migration agency put the death toll at least 50, with 16 survivors.