LVIV, Ukraine (AP) – Russian forces are pressing their assault Ukrainian cities, hitting a building near the western city of Lviv’s airport with missiles, as world leaders push for an investigation of the Kremlin’s repeat attacks on civilian targets. Rescue workers are still searching for survivors in the ruins of a theater that was serving as a shelter in the besieged southern city of Mariupol. And in Merefa, near the northeast city of Kharkiv, at least 21 people were killed when Russian artillery destroyed a school and a community center. The World Health Organization has verified 43 attacks on hospitals and health facilities in Ukraine.