Russia-Ukraine war: Key things to know about the conflict

Russian troops have stepped up their bombardment of the besieged port city of Mariupol, with Ukrainian officials saying a strike flattened an art school used as a shelter by hundreds of civilians

Russian troops stepped up their bombardment of the besieged port city of Mariupol on Sunday, with Ukrainian officials saying a strike flattened an art school used as a shelter by hundreds of civilians.

Mariupol continues to bear some of the war’s greatest suffering. Ukrainian President Volodymyr Zelenskyy early Sunday accused Russia of war crimes over its siege, describing the attack on the city as “a terror that will be remembered for centuries to come.”

In his nightly address to the nation, Zelenskyy said Ukraine is interested in peace, and that ongoing talks with Russia are “not simple or pleasant, but they are necessary.” He has sought to meet directly with Russian President Vladimir Putin, to no avail.

Pope Francis on Sunday denounced Russia’s “repugnant war” against Ukraine as “cruel and sacrilegious inhumanity.”