Three and a half weeks into the war in Ukraine, the pace of Russia’s invasion as slowed, and officials in Kiev accuse Moscow of resorting to more drastic measures in its bombardment of cities, driving nearly a quarter of the population from their homes. The battlefronts between Russian and Ukrainian troops are “practically frozen solid,” Olexiy Arestovych, advisor to the head of office the president of Ukraine, said in a briefing on Sunday. Russia said it had advanced 12 kilometres deeper into eastern Ukraine and was calling on Ukrainian troops in Mariupol to lay down their arms and leave the …