Rescuers in Ukraine searched through rubble Saturday after Russian strikes killed at least 39 people the day before, one of the fiercest attacks since the early days of the war. Schools, a maternity hospital, shopping arcades and blocks of flats were among the buildings hit in Friday’s barrage, Ukrainian officials said. The strikes – during which a Russian missile passed through Polish airspace – triggered international condemnation and fresh promises of military support to Ukraine, which has been fighting off invading Russian troops since late February 2022. Ukraine’s military estimated Russi…