Russian investigators receive more than 100 missing person reports after Moscow concert hall attack CNNAnalysis | Putin sees Kyiv in Moscow terrorist attack. But ISIS is its own story. The Washington PostRussia Doubles Down on Blaming Concert Massacre on Ukraine and the West The Wall Street JournalUkraine war updates: Russia says it's 'hard to believe' Islamic State group behind terror attack; death toll rises to 140 CNBCRussia terrorist attack: Why