Ukrainian officials say at least 21 civilians including two children were killed by a Russian airstrike in Sumy overnight. SUBSCRIBE to ABC NEWS: https://bit.ly/2vZb6yP Watch More on http://abcnews.go.com/ LIKE ABC News on FACEBOOK https://www.facebook.com/abcnews FOLLOW ABC News on TWITTER: https://twitter.com/abc #ABCNews #Poland #AmericanFighterJets #Ukraine