have captured kherson, a major strategic city in southern ukraine. there are new images that show russian military vehicles parked in a main square. ukrainian defense officials deny kherson has fallen. cnn has not been able to independently verify the russian claims. >> so just a short time ago, president zelenskyy claimed 6,000 russian soldiers have been killed since the invasion seven days ago. 6,000. now, cnn cannot confirm that number. just into cnn, i want to show you new video. this is at a nuclear power plant. and the on the road here are russian -- sorry, ukrainian plant workers and citizens. and what they're doing, you can see in the distance there, they are blocking or trying to block a russian military advance toward the nuclear power plant. so ukrainians filling the