Drone strikes hit three merchant vessels in the Black Sea within days, leaving several sailors dead or missing: a Turkish freighter carrying Ukrainian grain sank off Romania's coast, killing two, while a Togo-flagged ship sank and a Palau-flagged ship caught fire off Bulgaria, with the crew of the Togolese vessel still missing after the search was called off. Ukraine's President Volodymyr Zelensky blamed Russia, which has not commented, and the ships were sailing in the countries' exclusive economic zones (waters beyond 12 nautical miles from shore, outside their sovereign territory) rather than the safer territorial waters. The attacks threaten a key Ukrainian export route, push up insurance costs and have drawn concern from the EU and Turkey, whose President Erdogan raised the issue in a call with Vladimir Putin.