authorities throughout the day." this was published on his facebook page about ten minutes there. but you see a pretty sternly worded message there for the 1.4 million residents of kharkiv. this is the second largest city in ukraine. the mayor coming out and telling people don't leave your homes, don't go to work, don't send your children to school. it's been a very busy few hours since this all started, don, and there is no sign at this stage that it is letting up. and while it's one thing to be hearing strikes like that, missile strikes, one can assume, it is quite another thing to see ground forces crossing. we haven't seen that yet. but that is certainly what people in this city so close to that border, don, will be bracing themselves for. >> clarissa, so it's sporadic, these strikes, as you say, sporadic and then it is a barrage and then it stops for a moment? >> that's exactly right.