Azov Concord sinks and Chelsea 3 is hit as drones strike two ships off Bulgaria

Drones struck two merchant ships in Bulgaria's Black Sea exclusive economic zone early on Tuesday 13 October, sinking one of them, Prime Minister Rumen Radev said. It is the second attack of its kind off the Bulgarian coast in a week.

The Maltese-flagged general cargo ship Chelsea 3, Ukrainian-owned and registered in Odesa, sent a distress signal at about 01:30 local time from a position some 18 nautical miles east of Byala, south of Varna. Her crew reported that three aerial drones hit the deck and hull. All 15 people on board, seven Ukrainian and eight Azerbaijani citizens, were rescued, and five were treated for minor injuries. The 2006-built ship was damaged but stayed afloat and was towed into Varna.

The second ship, identified as the Turkish-owned Azov Concord, a 2008-built general cargo ship under the flag of St Vincent and the Grenadines, was hit about 17 nautical miles off Krapets on Bulgaria's northern coast and sank. One crew member was rescued and the search for the others continued. The number of people on board has not been disclosed.

Who is behind the attacks?

Radev called an emergency meeting of the cabinet's security council and described the attacks as "absolutely unacceptable". He said there was no clear evidence against any party, but that "logic indicates that the result is in favour of the Russian Federation". Bulgaria will summon the Russian ambassador, Eleonora Mitrofanova, and Radev said he would speak to NATO Secretary General Mark Rutte and keep asking allies for help to trace where the drones came from and to strengthen air and sea surveillance.

Rutte said NATO had already strengthened its posture on the eastern flank and would adjust its defences "as needed". European Commission President Ursula von der Leyen condemned the attacks and said those responsible should be held accountable. Ukraine's foreign minister Andrii Sybiha blamed Russia, and President Volodymyr Zelensky said Ukraine's military was not operating near the locations. Russia did not immediately comment.

How does this fit the pattern in the western Black Sea?

On 6 October drones struck two ships in the same economic zone. The Togo-flagged Alfa Watan sank with the apparent loss of all ten crew, and the Palau-flagged Able was badly damaged; her 18 crew were rescued. A day earlier the Turkish-owned grain carrier Royad Mammadov, bound from Izmail to Italy, sank off Romania after a strike that killed two seafarers, including her master. Those attacks are covered in our report on the Alfa Watan sinking.

Neither Bulgaria nor Romania has formally attributed any of the strikes, all of which took place in exclusive economic zones rather than territorial waters. More than 200 attacks on ships have been reported in the Black Sea this year.

This story is part of the Maritime Briefing of 13 October 2026.