Ukraine accused Russia on Thursday of using strategic bombers to hit a civilian grain vessel with a missile in the Black Sea in NATO member Romania's maritime economic zone, in what it described as a "brazen attack" on freedom of navigation.

The Saint Kitts & Nevis-flagged bulk carrier Aya was reportedly struck by a Russian missile in the Black Sea. The ship, managed by Athens-based VRS Maritime Services, was last seen off the Romanian port of Constanta.