Russian forces shelled an apartment block in Ukraine’s Donetsk region late Saturday, officials told Reuters, killing 15 people and trapping more than 24. The attack came in three spurts, with the rockets leaving some residents hiding in the basement until the barrage stopped. “We sat there all night until this morning,” one resident told Reuters. Ukraine slammed the move as a “terrorist attack,” while Russia denied it was targeting citizens. The shelling came as Russia kept up its offensive in the Donbas region, where Donetsk is located, as part of its quest to claim the territory. It also came as the country has struggled to refresh its troops, with a report in The New York Times noting its lackluster mobilization efforts. “It is basically desperate to get more men using any means possible,” an analyst told the Times.