Russia will observe a national day of mourning on Sunday (March 24) after a massacre in a Moscow concert hall that killed more than 130 people. The attack has been claimed by the Islamic State group. Three days earlier, Putin had publicly dismissed a US warning of an "imminent" attack in Moscow as propaganda designed to scare Russian citizens. The US embassy in Russia had warned on March 7 that "extremists have imminent plans to target large gatherings in Moscow, to include concerts".
