GENEVA (AP) — At least 73 Europe-bound migrants are missing and presumed dead in a shipwreck off Libya, the United Nations migration agency said Wednesday.

The U.N. International Organization for Migration said in a statement that the wreck took place Tuesday, and that Libya authorities have retrieved at least 11 bodies.

Seven migrants survived the shipwreck and made it to Libyan shores, the U.N. said, in “extremely dire conditions.” They were taken to a hospital.

Tuesday’s shipwreck was the latest sea tragedy in the central Mediterranean, a key route for migrants.

Libya has in recent years emerged as the dominant transit point for migrants from Africa and the Middle East trying to make it to Europe. The oil-rich country plunged into chaos following a NATO-backed uprising that toppled and killed longtime autocrat Moammar Gadhafi in 2011.