Russian officials said Sunday that Moscow is still awaiting official confirmation from Ukraine that a planned exchange of 6,000 bodies of soldiers killed in action will take place, reiterating allegations that Kyiv had postponed the swap. On the front line in the war, Russia said that it had pushed into Ukraine’s Dnipropetrovsk region.

Photos showed burnt and partially destroyed houses and vehicles, and rescuers carrying the injured to safety and removing debris.

Air assaults on Saturday killed at least four people. Kharkiv’s mayor described an overnight strike as “the most powerful attack” since the beginning of the war.