Ukraine Thursday accused Russia of deliberately targeting civilians after 30 people were killed when two buses were blown up in the frontline city of Kramatorsk, in one of the deadliest attacks in weeks. President Volodymyr Zelensky vowed that it “will not go unanswered” after photos posted by local authorities showed the burnt-out metal shell of the vehicles, with bodies and debris strewn across the road. “Russia is trying to destroy all life in (the) Donbas (region) and the world must respond to this,” he wrote on Telegram, warning the death toll could rise. US Secretary of State Marco Rubio meanwhile warned that the current stalemate after nearly five years of fighting was “very dangerous” and could lead to escalation. But Zelensky said he hoped Ukrainian negotiators, who were heading to the US, could persuade Washington to put more pressure on Russia. Last weekend he disclosed that Washington wanted technical-level talks between the two sides by the end of October. The Kramatorsk strikes came just a day after five young children were among 22 killed when a Russian missile struck a five-storey apartment block in Pryluky, in the northern Chernigiv region. “The Russians are deliberately targeting civilians,” Donetsk governor Vadym Filashkin said, accusing Moscow of flouting “every conceivable rule of warfare and norm of international humanitarian law”. Kramatorsk City Council called it “yet another horrific crime committed by the Russian army against the civilian population,” adding there were “absolutely no military targets” in the area. Three more people were killed in shelling at a nearby village, the emergency services said. There has been mounting concern about the increase in civilian deaths and injuries as both sides step up long-range attacks. The UN has verified more than 17,000 civilian deaths but says the real number is considerably higher. At least 534 people have died in Kyiv since the 2022 invasion, according to the city state administration’s data seen by AFP Thursday. Last week, Zelensky said his Russian counterpart Vladimir Putin had sanctioned massive attacks on civilian areas, a claim the Kremlin denies. But touring the site of the Pryluky attack Thursday, visiting UK foreign minister Ed Miliband said there was “no clearer sign of Putin’s evil, evil intent and strategy in this conflict”. “Putin once said that he was going to win on the battlefield,” he told reporters, as London announced more sanctions on Moscow. “He is trying to win by terrorising civilians.” Zelensky urged the US to “raise the pressure” on Russia, including through providing better air defence systems, to force Putin to the negotiating table. Ukraine’s capital Kyiv has come under increasing attack, including on Wednesday from a barrage of Russian ballistic and cruise missiles, and fast-moving, jet-powered drones. For the first few years of the conflict, Kyiv had been relatively spared from the devastation wrought on the frontline. But key transport bridges and the rail network have now been hit and rolling power cuts introduced after energy infrastructure was targeted. Power disruptions forced the temporary suspension of the Kyiv metro Thursday. Mayor Vitali Klitschko told AFP in an interview that the city was in “survival” mode as winter approaches. Russia claims the eastern Donetsk region as its own and the area has been the epicentre of fighting but it has not yet captured Kramatorsk. The city, which had a pre-war population of some 150,000, has been used as a logistics and supply hub for the Ukrainian military and is part of the so-called “fortress belt” which troops are fighting to retain.