Drones sink ship off Bulgaria's coast as Black Sea becomes NATO's newest front line

Two commercial ships were struck by drones in Bulgaria's Black Sea waters before dawn on Tuesday, sinking one vessel and damaging another in the third such attack on shipping off the Bulgarian coast in just over a week. The strikes, which Bulgarian officials said they could not yet attribute to a specific party, prompted an emergency security meeting in Sofia and a sharp condemnation from the European Commission, which said the Black Sea "has become another front of escalation" in Russia's war against Ukraine.

Prime Minister Rumen Radev said a distress call came in at around 1:30 a.m. local time from a vessel roughly 15 to 18 nautical miles off Bulgaria's northern coast, near the towns of Byala and Krapets. One ship, identified by Bulgarian media as the Azov Concorde, a Turkish-owned, St Vincent and the Grenadines-flagged vessel, was hit and sank; only one of its crew had been rescued by Tuesday morning, and the fate of the rest remained unclear. A second vessel, the Chelsea 3, a Ukrainian-owned, Maltese-flagged ship registered in Odesa, was struck by three aerial drones and set ablaze but stayed afloat long enough to be towed into the port of Varna.

Two ships, one sunk, in Bulgaria's economic zone

All 15 crew members of the Chelsea 3, seven Ukrainian and eight Azerbaijani nationals, were pulled from the water by Bulgarian border police, according to Al Jazeera's account of the rescue. Five of them were treated for minor injuries; none was seriously hurt. Radev told reporters the attack took place in Bulgaria's exclusive economic zone, not its territorial waters, but said that distinction offered little comfort. "Another attack in the immediate vicinity of Bulgarian territorial waters" was, he said, "absolutely unacceptable."

The prime minister convened an emergency meeting of the government's security council within hours of the strike. He said Bulgaria would summon Russia's ambassador, Eleonora Mitrofanova, for an explanation, and that he intended to speak by phone with NATO Secretary-General Mark Rutte, whom Radev had hosted in Brussels earlier this year to discuss Bulgaria's contribution to the alliance's eastern flank, including the Black Sea. Radev stopped short of naming a culprit. "I cannot say with certainty which side the drones came from," he said, "but logic suggests the outcome benefits the Russian Federation."

A sea at war for a second week running

Tuesday's strikes were not an isolated episode. On October 6, drones hit two other merchant ships in the same stretch of Bulgarian waters, sinking the Togo-flagged Alfa Watan and setting fire to the Palau-flagged Able. All 18 crew of the Able were evacuated by a Bulgarian ferry, but the search for the Alfa Watan's crew was called off days later with no survivors found, according to reporting by the Sofia Globe. A week before that, on October 5, a Turkish-owned grain carrier, the Royad Mammadov, caught fire and sank in Romania's exclusive economic zone while sailing corn from Ukraine's Izmail port to Italy; Romanian authorities said its captain and one other crew member were killed and eleven more were rescued, in an attack Ukraine's president blamed on Russian drones.

The pattern fits a broader shift in Russia's war against Ukraine, now well into its fifth year, from strikes on Ukrainian ports and grain terminals to attacks on merchant traffic further out at sea, including vessels flagged to third countries with no connection to either belligerent. The International Maritime Organization had already condemned what its secretary-general, Arsenio Dominguez, called "unwarranted attacks on civilian merchant vessels arising from geopolitical conflicts," warning that seafarers "should not become casualties of conflicts they are not party to." Bulgaria and Romania, both NATO and EU members bordering the Black Sea, have watched the toll rise with each passing month, even as neither Kyiv nor Moscow has been formally found responsible for any single incident.

Seafarers from four countries caught in the crossfire

The crews put at risk this week were not Bulgarian, Russian or Ukrainian nationals in any uniform sense; they were ordinary merchant sailors from across the region and beyond. The Chelsea 3's crew included Ukrainians and Azerbaijanis; the Alfa Watan and Able, earlier this month, carried Indian and Turkish seafarers; the Royad Mammadov's dead and rescued were Azerbaijani and Indian nationals working a commercial grain run, not a military one. Shipowners and insurers active in the Black Sea now face a region where a vessel's flag, cargo and crew can originate in half a dozen countries with no stake in the underlying war, yet still be struck.

• Three attacks on merchant shipping in Bulgarian and Romanian waters in eight days: October 5, October 6 and October 13.
• At least two confirmed dead, from the October 5 sinking of the Royad Mammadov off Romania.
• Multiple crew members from the Alfa Watan and the Azov Concorde unaccounted for as of Tuesday.
• Four nationalities represented among the rescued and missing crews this month: Ukrainian, Azerbaijani, Indian and Turkish.

Condemnation from Brussels, caution from Sofia

European Commission President Ursula von der Leyen issued one of the sharpest statements yet from an EU leader on the string of attacks. She said she "strongly condemned" the drone strikes and that those responsible should be held accountable.

"The Black Sea has become another front of escalation" in Russia's war on Ukraine, von der Leyen said, adding that the European Union stood in full solidarity with Bulgaria.

Ukraine's foreign minister, Andrii Sybiha, was more direct in assigning blame, writing on social media that the attack reflected "Moscow's deliberate disregard for civilian lives" and calling on Kyiv's partners to tighten sanctions on Russia and do more to protect freedom of navigation in the Black Sea, according to NBC News's report on the morning's events. Russian officials had made no public comment on the Tuesday attack by the time this article was published. Bulgaria's own position has been markedly more cautious than Kyiv's: both Radev and President Iliana Iotova have declined to formally assign blame while an investigation continues, even as both have said the war in Ukraine is the root cause of the deteriorating security environment in Bulgaria's waters. Bulgaria's Foreign Minister, Velislava Petrova-Chamova, has likewise condemned the repeated strikes on merchant shipping without naming a party responsible, Bulgarian state news agency BTA reported.

Domestically, the attacks have reopened a political argument in Sofia. Opposition figures accused Radev's government of a "toothless" response that has failed to deter further strikes, while one lawmaker from the nationalist Vazrazhdane party said the war "is now in our yard." Radev's government had already announced, after the October 6 attack, that it would buy five additional surface-to-air missile systems, a move framed at the time as a direct response to the deteriorating security picture at sea.

What happens next

Bulgaria says it is seeking both NATO and EU assistance to investigate the origin of the drones and to strengthen air and sea surveillance along its coast, a request Radev said he would press directly with Rutte. NATO has so far been largely silent in public on the specific attacks, previously referring questions about the October 6 strikes back to Bulgarian authorities, and it remains to be seen whether Tuesday's sinking changes that posture. A joint Bulgarian-Romanian proposal for a civilian Black Sea maritime security centre, aimed at improving surveillance and protecting infrastructure from exactly this kind of attack, has been under discussion for months without a firm timeline for when it might become operational.

For now, insurers and shipowners are left weighing whether the Black Sea's southern and western waters, once considered a comparatively safe corridor for grain and bulk cargo compared with the contested north, are becoming as dangerous as the war zone itself. With no formal attribution for any of the three attacks this month, and with Moscow silent and Kyiv denying direct involvement, the question of who is firing into Bulgarian and Romanian waters, and why commercial vessels from countries with no part in the war keep being hit, remains open even as the toll climbs.