Eleven sailors were missing at sea on Tuesday from a ship sunk by a drone attack off the coast of Bulgaria, possibly the second deadly sinking of a cargo vessel in the area in a week, prompting Bulgaria to summon Russia's ambassador.Two cargo ships were hit by drones overnight and one was sunk…<p><p>https://www.marinelink.com/news/black-sea-drone-attack-sinks-cargo-ship-543634</p></p>