UN humanitarian chief Martin Griffiths (5th R) reacts at the site of a mass grave that Ukrainians had dug near a church on April 7, 2022 during his three-hour visit in Bucha, a day after he visited Moscow, where he met with officials to discuss the humanitarian situation in Ukraine, more than a month into the Russian invasion. - Griffiths said that investigators would probe civilian deaths uncovered after Russian troops withdrew. Evidence of civilian killings in Bucha and other towns around Kyiv - which Ukraine has blamed on Russian troops, allegations denied by Moscow - have shocked the world and triggered calls for new sanctions on Moscow. Russia's President has denied any responsibility for civilian deaths, accusing Ukrainian authorities of "crude and cynical provocations" in Bucha. (Photo by RONALDO SCHEMIDT / AFP)