Russian troops entered the outskirts of the Ukrainian city of Sievierodonetsk, a regional governor said on Monday, describing the fighting as “very fierce” in a city that become a key objective for Moscow’s offensive in the Donbas. “The Russians are advancing into the middle of Severodonetsk. The fighting continues. The situation is very difficult,” the Lugansk regional governor Sergiy Gaiday said in a statement on social media. Incessant shelling has left Ukrainian forces defending ruins in Sievierodonetsk, but their refusal to withdraw has slowed a massive Russian offensive across the Donbas region in eastern Ukraine. Having failed to take the capital Kyiv in the early phase of the war, Russia is seeking to consolidate its grip on Donetsk and Luhansk, the two provinces that make up the Donbas - large parts of which are already controlled by Moscow-backed separatists. “Some 90 per cent of buildings are damaged. More than two-thirds of the city’s housing stock has been completely destroyed. There is no telecommunication,” Ukrainian President Volodymyr Zelensky said in a televised speech Sunday. “Capturing Sievierodonetsk is a fundamental task for the occupiers … We do all we can to hold this advance.” The city’s mayor said the fighting had knocked out power and mobile phone service and forced a humanitarian relief centre to shut down because of the dangers. ‘Now I am a beggar’: fleeing the Russian advance in Ukraine Residents remaining in the city, which had a pre-war population of around 100,000, risked exposure to shelling just to get water from a half-dozen wells, Mayor Oleksandr Striuk said. Striuk estimates that 1,500 civilians in the city have died since the war began, from Russian attacks as well as from a lack of medicine or treatment. The deteriorating conditions raised fears that Sieverodonetsk could become the next Mariupol, a city on the Sea of Azov that spent nearly three months under Russian siege before the last Ukrainian fighters surrendered. Sievierodonetsk is located 143km (89 miles) south of the Russian border. Russia also stepped up its efforts to capture the nearby city of Lysychansk, where civilians rushed to escape persistent shelling. The two eastern cities span the strategically important Siverskiy Donetsk River. They are the last major areas under Ukrainian control in Luhansk province. The “liberation” of the Donbas, an industrial region which includes Luhansk and Donetsk, is an “unconditional priority” for Russia, Foreign Minister Sergey Lavrov said on Sunday. He reiterated Moscow’s claims that its “special military operation” in Ukraine is to demilitarise its neighbour after waves of Nato’s eastward expansion and cleanse it of what it sees as “Nazi”-inspired nationalism. Kyiv and Western countries see those claims as baseless pretexts for a land grab. “Yes, people are being killed,” Lavrov said. “But the operation is taking so much time primarily because Russian soldiers taking part are under strict orders categorically to avoid attacks and strikes on civilian infrastructure.” Zelensky visits frontline in east for first time since invasion began The invasion, now in its fourth month, has killed thousands of people in Ukraine and displaced millions. According to the United Nations, more than 6.7 million refugees have fled Ukraine since February 24. There are some 14,388 cases of Russian alleged war crimes being probed by Ukraine’s Prosecutor General’s Office and several Russian soldiers have pleaded guilty in cases of shelling Ukraine and killing civilians. The Institute for the Study of War, a think tank based in Washington, questioned the Kremlin’s strategy of assembling a huge military effort to take Sieverodonetsk, saying it was proving costly for Russia and would bring few returns. “When the battle of Sieverodonetsk ends, regardless of which side holds the city, the Russian offensive at the operational and strategic levels will likely have culminated, giving Ukraine the chance to restart its operational-level counteroffensives to push Russian forces back,” the institute said late on Saturday. Russia test-fires latest hypersonic Zircon missile In Mariupol on Sunday, an aide to its Ukrainian mayor alleged that after Russia’s forces gained complete control of the city, they piled the bodies of dead people inside a supermarket. The aide, Petro Andryushchenko, posted a photo on the Telegram messaging app of what he described as a “corpse dump” in the occupied city. It showed bodies stacked alongside closed supermarket counters. “Here, the Russians bring the bodies of the dead, which were washed out of their graves during attempts to restore the water supply, and partially exhumed. They just dump them like garbage,” he wrote. It was not immediately possible to verify his claim. Reuters and Associated Press