Eleven sailors are missing after a cargo ship sank following a drone attack off the coast of Bulgaria, prompting the country to summon Russia’s ambassador over the incident, the second deadly sinking in the area in a week.

Bulgarian officials said two cargo ships were hit by drones overnight on Tuesday, with one sinking. Five crew members from the sunken vessel were rescued, while 11 remained missing.

Although Bulgaria stopped short of directly accusing Russia of carrying out the attacks, Prime Minister Rumen Radev said their outcome benefited Moscow.

“This is absolutely unacceptable — another attack in the immediate vicinity of Bulgarian territorial waters,” Radev said in a televised address.

Russia had not immediately commented on the incidents as of Tuesday. Ukraine and the European Union also condemned the attacks.

European Commission President Ursula von der Leyen said the incidents showed that the Black Sea had become another front in Russia’s war against Ukraine.

“The Black Sea has become another front of escalation of the Russian war in Ukraine,” she wrote on X, adding that those responsible should be held accountable.

Ukraine’s Foreign Minister Andrii Sybiha also condemned the strike, accusing Moscow of deliberately disregarding civilian lives.

“The Black Sea is a lifeline for global food security. Russia is attacking it to weaponise hunger and hold the world hostage,” Sybiha wrote on X on Tuesday.

Bulgarian media identified the sunken vessel as the Azov Concord, while its Turkey-based manager was not immediately available for comment.

Another vessel, the Chelsea 3, sailing under the Maltese flag, was struck by three drones overnight, according to Bulgarian officials. All 15 crew members, comprising seven Ukrainians and eight Azerbaijanis, were rescued, with none seriously injured.

The latest incident follows another deadly sinking a week earlier, when nine Syrian sailors and one Egyptian sailor were lost at sea after a ship was struck by drones in Bulgaria’s exclusive economic zone in the Black Sea. Another vessel was hit during the same incident, but its crew was rescued.

The attacks come as Black Sea shipping has increasingly become entangled in the prolonged war between Russia and Ukraine, which began with Moscow’s full-scale invasion in 2022.

Both countries are among the world’s largest grain exporters, making the security of shipping routes in the Black Sea important to global food supplies.

Russia has been bombing Ukrainian Black Sea ports, forcing Ukraine to rely increasingly on river ports along the Danube and shipping routes close to the coasts of NATO members Bulgaria and Romania.

Ukraine, meanwhile, has increasingly targeted Russian grain-exporting vessels in other parts of the Black Sea and the Sea of Azov, near the mouth of the Don River. (Arise News)