Biggest Terrorist attack in Russia's Moscow,60 killed more than 100 injured

ISIS Claims responsibility, ISIL the hardline group that once sought control over Iraq and Syria.

The Concert Hall, one of them most popular in Moscow, Can Hold some 6200 people & it was fully Booked.

Another witness, speaking to the news agency described terror and panic inside venue. "A stampede began. Everyone ran to the escalator, Everyone was screaming , everyone was running

the attack left the concert hall in flames and its roof in a state of collapse, was one of the worst in Russia since 2004 Beslan school siege in which more than 330 People killed

all those involved in this attack will pay a very heavy price: Putin