Russia is in the process of equipping its new nuclear submarines with hypersonic Zircon missiles, the head of Russia’s largest shipbuilder told the RIA state news agency in an interview published on Monday. “Multi-purpose nuclear submarines of the Yasen-M project will … be equipped with the Zircon missile system on a regular basis,”, Alexei Rakhmanov, chief executive officer of the United Shipbuilding Corporation (USC), told RIA. “Work in this direction is already underway.” Yasen-class submarines, also known as Project 885M, are nuclear-powered cruise missile submarines, built to replace Soviet-era nuclear attack submarines as part of a programme to modernise the army and fleet. The sea-based Zircon hypersonic missiles have a range of 900 km (560 miles), and can travel at several times the speed of sound, making it difficult to defend against them. President Vladimir Putin said earlier this year that Russia would start mass supplies of Zircon missiles as part of the country’s efforts to boost its nuclear forces. The Russian multi-purposes frigate Admiral Gorshkov, which has tested its strike capabilities in the western Atlantic Ocean earlier this year, has been already equipped with Zircon missiles. Meanwhile, a Russian warship fired warning shots at a cargo ship in the southwestern Black Sea as it made its way northwards, the first time Russia has fired on merchant shipping beyond Ukraine since exiting a landmark UN-brokered grain deal last month. In July, Russia halted participation in the Black Sea grain deal that allowed Ukraine to export agricultural produce via the Black Sea. Moscow said that it deemed all ships heading to Ukrainian waters to be potentially carrying weapons. On Sunday, Russia said in a statement that its Vasily Bykov patrol ship had fired automatic weapons on the Palau-flagged Sukru Okan vessel after the ship’s captain failed to respond to a request to halt for an inspection. Russia said the vessel was making its way toward the Ukrainian port of Izmail. Refinitiv shipping data showed the ship was currently near the coast of Bulgaria and heading toward the Romanian port of Sulina. A senior adviser to Ukrainian President Volodymyr Zelenskiy said the incident was a “clear violation of international law of the sea, an act of piracy and a crime against civilian vessels of a third country in the waters of other states.” The adviser, Mykhailo Podolyak, added on X, the social media platform formerly known as Twitter, that “Ukraine will draw all the necessary conclusions and choose the best possible response.” Zelenskiy did not mention the incident in his nightly video address. Natalia Humeniuk, spokesperson for the southern military command, stressed that the Russian statement had not been confirmed by other official sources. “I believe that attention should be drawn to this and the peculiarities of hybrid warfare should be kept in mind,” she said in televised remarks. “This statement could be a signal to all civilian vessels in the Black Sea,” she said, and called for all transportation and navigation there to be conducted under international guarantees. Russia, she added, was trying to assert its right to stop a ship or deploy aircraft in the Black Sea and “face no consequences.”