Ukraine has struck Russian naval targets and port infrastructure in the Crimean city of Sevastopol, in what appeared to be the biggest attack of the war on the home of the Russian navy’s Black Sea fleet. A Ukrainian intelligence official said a large vessel and a submarine struck in the attack were so badly damaged as to be likely beyond repair. The pre-dawn strike highlighted Kyiv’s growing missile capabilities as Russia continues to bombard Ukraine from afar with long-range missiles and assault drones. “We confirm a large landing vessel and submarine were hit. We do not comment on the means [used] for the strike,” Ukrainian military intelligence official Andriy Yusov told Reuters. Yusov later told national television: “Those are significant damages. We can now say that with a high probability they are not subject to restoration.” Russia’s defence ministry said in statement that Ukraine had attacked a Black Sea shipyard with 10 cruise missiles and three uncrewed speedboats in the early hours, damaging two military vessels that had been undergoing repairs. It said it downed seven of the incoming missiles and that the attack boats had been destroyed by a Russian patrol ship. An image circulated online and verified by Reuters showed a docked vessel that had sustained serious damage. Yuri Ihnat, spokesperson for Ukraine’s air force, was doubtful of the Russian assertion that its units had downed most of the incoming missiles. “It’s hard to say how many they were capable of downing,” he told national television. “It is important not to underestimate their anti-aircraft units. Perhaps they destroyed them. Perhaps not.” Retired Ukrainian navy captain Andriy Ryzhenko, speaking to Reuters by telephone, said: “It really is the biggest attack on Sevastopol since the beginning of the war.“ The city is home to the Black Sea fleet, which the Kremlin uses to project power into the Middle East and Mediterranean and – during the war in Ukraine – to impose a de facto blockade on Ukraine’s seaborne food exports via the Turkish straits. Putin recently said he would not renew a deal allowing Ukraine to export grain safely through the Black Sea until the west met Moscow’s demands concerning its own agricultural exports. “The demilitarisation of the Russian Black Sea fleet is a real long-term guarantee of security for regional trade routes and the ‘grain corridor’,” said Mykhailo Podolyak, an adviser to Zelenskyy. “This is the only correct response to Russia’s attempts to turn hunger into a weapon and the only way to ensure uninterrupted grain supplies to the countries of the east and Africa.” Ukraine has tried to push back against the fleet’s naval power by attacking with sea drones packed with explosives, but Russia has continued to use its warships for missile attacks on Ukraine throughout the more than 18-month-old war. It was not clear what kind of missile was used by Kyiv in the attack on Sevastopol, which lies about 300km (185 miles) from Ukraine’s Black Sea port of Odesa. Ryzhenko said Ukraine may have used domestically made Neptune anti-ship missiles that had been modified to work against ground targets. British-supplied Storm Shadow cruise missiles were another possibility, he said. The Ukrainian military, which launched a counteroffensive in early June, took the unusual step of publicly claiming responsibility for the strike, something it does not typically do with respect to attacks on Russia or the Crimean peninsula. “On the morning of 13 Sept, the Ukrainian armed forces conducted successful strikes on naval assets and port infrastructure of the occupiers at the docks of temporarily occupied Sevastopol,” it said on Telegram. Mikhail Razvozhayev, the Moscow-installed governor of Sevastopol, the largest city in Crimea and a major Black Sea port, said on Telegram that at least 24 people had been injured. He posted a night photo of flames engulfing what appeared to be port infrastructure. Russian Telegram channels posted videos and more photos of flames at a facility by the water.