People, some carrying bags and suitcases, walk in a metro station in Kyiv early on February 24, 2022. Air raid sirens rang out in downtown Kyiv on Thursday as cities across Ukraine were hit with what Ukrainian officials said were Russian missile strikes and artillery. - Russian President Vladimir Putin announced a military operation in Ukraine on Thursday with explosions heard soon after across the country and its foreign minister warning a "full-scale invasion" was underway. (Photo by Daniel LEAL / AFP)