Drone strikes hit two cargo vessels within 18 nautical miles of the Bulgarian coast early Tuesday, sinking one ship and leaving eleven crew members missing — the most direct escalation yet of the Black Sea drone campaign into the approaches of a NATO member state.

Bulgaria responded by summoning Russian ambassador Eleonora Mitrofanova, abandoning its earlier reluctance to assign blame. Prime Minister Rumen Radev's office framed the reasoning in commercial terms: "There's no logic in Ukraine destroying its own ships, and the results of these strikes work to Russia's advantage."

The statement went further on cost. "Although not a party in the war, Bulgaria is suffering significant economic and financial damage," it read. "Attacks in the Black Sea have already led to increased risks for commercial shipping, higher insurance costs, and even refusals to transport cargo to Bulgarian ports."

That last claim — carriers refusing Bulgarian port calls outright — is the sharpest signal for forwarders, even if the government offered no volume figures to quantify it.

What happened off Byala and Krapets?

The Malta-flagged, Ukrainian-owned Chelsea 3 was struck around 01:30 a.m. Tuesday, 18 nautical miles (33 kilometers) off the coast near Byala. Its 15-member crew of Ukrainian and Azerbaijani sailors reported an attack by three aerial drones. The ship remains afloat; it was sailing from Giresun, Turkey, to the Moldovan river port of Giurgiulesti, according to Maritime.bg.

The second vessel, identified by the Bulgarian President's office as the Guinea-Bissau-flagged HS Dignity, sank 17 miles from the village of Krapets. AIS data shows it had traveled from Mostanagem, Algeria, to Braila, Romania. Five sailors have been rescued; the Dobrich regional governor told BNR public radio that eleven crew members remain missing. Three people were admitted to the maritime hospital in Varna, the Defense Ministry said.

Both strikes occurred just outside Bulgaria's 12-mile territorial water line — close enough that the distinction offers operators little comfort.

The attacks follow strikes in Bulgaria's exclusive economic zone last week, in which one ship sank in three minutes with no survivors — potentially among the deadliest non-battlefield incidents of the entire war. A corn carrier was also hit in Romania's economic zone last week.

What does this mean for grain flows?

Wheat prices were mostly steady on Tuesday, and analysts caution against reading a market shock into the headlines. "More attacks don't really alter the picture much, bar reminding the market that Black Sea shipping does have its dangers, and that a Russia-Ukraine resolution is a way off," said Mike Verdin, senior markets consultant at CRM AgriCommodities.

The risk is slower-burning: premium erosion rather than price spikes. Preslav Raykov, Global Trading Manager at Magic Flame Group, said the attacks are already shifting risk perceptions among grain traders new to the region. If strikes intensify, he warned, export activity from Romania and Bulgaria could suffer — Bulgaria being a large net wheat exporter with limited internal demand to absorb diverted cargoes.

How are Bulgaria and NATO responding?

Mitrofanova told Radev she understood his logic but had no information from the Russian defense ministry on the attacks, and did not rule out provocation by a third country — a caveat that leaves Sofia's attribution officially unconfirmed.

Bulgarian President Iliana Yotova, who convened a security meeting last week, called the trend explicit: "The escalation of the war led to an increase of the incidents near the Bulgarian shores and is turning the Black Sea into a military zone. Freedom of shipping and safety of supply chains are seriously threatened, generating significant risks to our country."

NATO Secretary General Mark Rutte said on X, after speaking with Radev: "We have already strengthened our posture along the eastern flank and will continue to monitor the security environment, adjusting our deterrence and defense posture as needed."

Radev raised Black Sea navigation guarantees at this week's EU leaders' meeting in Brussels, and the defense ministers of Bulgaria, Romania and Turkey held a series of calls Monday. The three states already run a joint mine-sweeping program in territorial waters and are working to expand it to cover underwater infrastructure.

None of that yet adds up to convoy protection or escort guarantees for merchant shipping. With wheat prices steady but refusals to call at Bulgarian ports already reported, the practical question for carriers and insurers is whether Tuesday's strikes mark a boundary or a baseline.