“Massive” Russian bombardment of Ukraine’s battleground eastern Lugansk region and key city Severodonetsk has been “hell” for soldiers there, Kyiv said, while insisting that defenders would hold “as long as necessary”. Moscow’s troops have been pummelling eastern Ukraine for weeks and are slowly advancing, despite fierce resistance from the outgunned Ukrainian military. With President Vladimir Putin’s forces tightening their grip on the strategically important city of Severodonetsk in the Donbas, its twin city of Lysychansk is now coming under heavier bombardment. “The Russian army is… just destroying everything” in Lysychansk, Sergiy Gaiday, governor of the Lugansk region, which includes both cities, wrote on Telegram. “It’s just hell out there,” after four months of shelling in Severodonetsk, across the Donets river, he wrote later. “Our boys are holding their positions and will continue to hold on as long as necessary,” he added. Pro-Russian separatists claimed they were close to surrounding both Lysychansk and Severodonetsk. “Over the past several days enormous work has been accomplished,” Andrei Marochko, an officer in the separatist army of Lugansk, told Russian state TV. Russian forces have been occupying villages in the area. Taking control of the two cities would give Moscow control of the whole of Lugansk, allowing them to press further into the Donbas. After being pushed back from Kyiv and other parts of Ukraine following their February invasion, Moscow is seeking to seize a vast eastern swathe of the country. In a briefing Wednesday, the Russian defence ministry claimed responsibility for a missile strike it said killed a number of Ukrainian troops in southern Mykolaiv. City mayor Oleksandr Senkevych told Ukrainian television that the strike hit two firms and a school as well as starting a blaze that authorities could not put out. In the central Ukrainian city of Zaporizhzhia, women were training to use Kalashnikov assault rifles in urban combat as Russian forces edged nearer. “Of course, when you can do something, it’s not so scary to take a machine gun in your hands,” said Ulyana Kiyashko, 29, after moving through an improvised combat zone in a basement. In his daily address Tuesday, Ukrainian President Volodymyr Zelensky accused the Russian army of “brutal and cynical” shelling in the eastern Kharkiv region, where the governor said 15 had been killed Tuesday. Aid group Doctors Without Borders (MSF) said it had gathered accounts of an “outrageous lack of care to distinguish and protect civilians”. Most patients it had evacuated by train blamed Russian or Russian-backed forces for a spectrum of gruesome injuries, it added. On the Russian side, officials said Wednesday two drones had hit an oil refinery in the Ukraine-bordering Rostov region, causing an explosion and a fire but no casualties. Away from the battlefield, Moscow summoned Brussels’ ambassador in a dispute with EU member Lithuania over the country’s restrictions on rail traffic to the Russian outpost of Kaliningrad. The territory is around 1,000 miles (1,600 kilometres) from Moscow, bordering Lithuania and Poland. By blocking goods arriving from Russia, Lithuania says it is simply adhering to European Union-wide sanctions on Moscow.