Two ships were hit by drones about 15 miles off Bulgaria's Black Sea coast on Oct. 13, with one sinking, Bulgarian Prime Minister Roman Radev said. The origin of the ships, the cargo and the origin of the UAVs remain unknown.

Two ships were hit by drones about 15 miles off Bulgaria's Black Sea coast on Oct. 13, with one sinking, Bulgarian Prime Minister Roman Radev said. The origin of the ships, the cargo and the origin of the UAVs remain unknown.