National day of mourning in Russia after concert hall massacre

Moscow (AFP) - Russia will observe a national day of mourning on Sunday after a massacre in a Moscow concert hall that killed more than 130 people, the deadliest attack in Europe to have been claimed by the Islamic State (IS) group. Russian President Vladimir Putin has vowed to punish those behind the "barbaric terrorist attack", saying four gunmen trying to flee to Ukraine had been arrested. Kyiv has strongly denied any connection, with Ukrainian President Volodymyr Zelensky accusing Putin of trying to shift the blame onto them.  Putin, in his first public remarks on the attack, made no refer...