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.

A Ukrainian army officer looks at his phone in a local train in Kyiv, Ukraine, Wednesday, Feb. 23, 2022. (Photo: AP)

Citizens were headed for underground metro stations to take shelter, AFP correspondents saw, as authorities declared martial law in the face of what they fear is a full-scale invasion.