Bulgaria is seeking stronger cooperation with Romania, Türkiye and its NATO and European Union partners after drone attacks struck two merchant vessels off its Black Sea coast on 13 October. One ship sank, with eleven crew members still missing in the latest reports available on Tuesday evening.

The Guinea-Bissau-flagged HS Dignity went down near Bulgaria’s northeastern coast. Five members of its sixteen-person crew were rescued. All fifteen sailors aboard the second vessel, the Malta-flagged Chelsea-3, survived. The incidents prompted emergency rescue operations and renewed demands for protection of commercial navigation. bta.bg

Bulgaria’s Transport and Communications Ministry said Chelsea-3 was attacked seventeen nautical miles east of Byala, while HS Dignity was struck seventeen nautical miles east of Shabla. According to the ministry, both vessels were travelling without cargo: Chelsea-3 towards Giurgiulești, Moldova, and HS Dignity towards Brăila, Romania. Merchant vessels nearby provided the first assistance to survivors of the sinking. bta.bg

Bulgarian public radio reported that four rescued HS Dignity sailors reached Varna aboard the naval tug Mizar on Tuesday evening. Regional authorities said the three Syrian nationals and one Egyptian were examined and were in good condition. The fifth survivor was being transported separately. БНР Новините

Responsibility remains contested. Ukrainian officials accused Russia, while Bulgarian Prime Minister Rumen Radev said the attacks benefited Moscow and sought allied assistance in establishing what happened. Russia’s ambassador said she had no information from the Russian Defence Ministry and suggested possible involvement by a third party. Those statements do not constitute an independently established attribution. Reuters

The diplomatic response is taking shape alongside the rescue effort. President Iliana Iotova said Bulgaria had coordinated a statement with Romania and Türkiye seeking an end to attacks on civilian and commercial infrastructure in the Black Sea. Sofia also intends to raise the matter before the United Nations Security Council. These remain diplomatic initiatives, rather than an agreed mechanism capable of enforcing safe passage. bta.bg

For the region, the immediate challenge extends beyond identifying the drones’ origin. The attacks occurred on routes connecting several countries’ ports, making maritime surveillance and emergency coordination shared concerns. Bulgaria and Romania have consequently called for closer cooperation with Türkiye to strengthen regional security and protect navigation