Russian President Vladimir Putin on Saturday announced March 24 as the day of mourning in the country and called the attack in the Crocus City Hall near Moscow, a barbaric terrorist act. As many as 143 people were killed while several close to a hundred others were injured after terrorists opened fire at them in a concert.   Russian President Vladimir Putin on Saturday announced March 24 as the day of mourning in the country and called the attack in the Crocus City Hall near Moscow, a barbaric terrorist act. As many as 143 people were killed while several close to a hundred others were injured after terrorists opened fire at them in a concert.