Key facts
- Two merchant vessels sank after being hit by drones in Bulgaria's exclusive economic zone on October 6 and October 13, 2026.
- Prime Minister Rumen Radev has been hesitant to formally accuse Russia of the attacks.
- Opposition lawmakers have criticized Radev's cautious stance toward Moscow.
- Analysts suggest Russia is testing Bulgaria as a potential weak link in NATO's southern flank.
Prime Minister Rumen Radev's balancing act between Bulgaria's NATO membership and maintaining ties with Moscow is under increasing pressure following drone attacks on merchant vessels in the country's exclusive economic zone. On October 6, 2026, two Turkish-managed ships, the Alfa Watan and the Chelsea 3, were hit by drones about 70 nautical miles east of Byala. The Alfa Watan sank, with 10 crew members presumed dead. On October 13, the HS Dignity sank after being hit by drones, with 11 sailors reported missing, while the Chelsea 3's crew was rescued. These incidents occurred amid escalating hostilities in the Black Sea, with Russia attempting to blockade Ukrainian trade. Radev's initial hesitation to directly blame Russia for the attacks drew criticism from opposition lawmakers and analysts, who suggest Moscow is testing Bulgaria as a weak link on NATO's southern flank. The maritime attacks follow other security-related incidents, including a fire at a Starlink facility near Sofia and explosions at arms facilities belonging to EMCO, a supplier to Ukraine.