[HIGHLIGHTS] Attack on concert hall near Moscow: Putin suggests Ukraine's involvement in the attack

Attack on concert hall near Moscow: Putin suggests Ukraine's involvement in the attack. Putin calls the attack near Moscow a "barbaric act" and draws a connection to Ukraine.

Meanwhile, IS publishes a photo of the alleged attackers. Putin ordered Sunday to be a nationwide day of mourning. The attack was the deadliest in Russia in years and left the concert hall a smoldering ruin. The extremist militia “Islamic State” (IS) claimed responsibility for the attack on Friday evening.