About 300 people were killed in the Russian airstrike last week on a Mariupol theater that was being used as a shelter, Ukrainian authorities said Friday in what would make it the war's deadliest known attack on civilians yet.
Meanwhile, Russian forces appear to have halted, at least for now, their ground offensive aimed at capturing the capital, Kyiv, and are concentrating more on the fighting for control of the Donbas region in the country's southeast, a senior US defense official said.
