A merchant ship sank in the Black Sea off NATO member Bulgaria after a drone strike, leaving its crew missing. Prime Minister Rumen Radev called the attack a gross violation of international law ▻ ↧ Drone sinks ship off Bulgaria, as fears grow about hybrid attacks b... The crew of a merchant ship ​was missing on Tuesday after the vessel sank in the Black Sea off NATO member Bulgaria following a drone strike ‌that Prime Minister Rumen Radev described as a gross violation of international law.