The terrorist group Islamic State (IS) has claimed responsibility for the mass shooting at a concert hall in Moscow on March 22 that has left at least 60 people dead.
The group announced their involvement in a Telegram post released after the attack
"Soldiers of the Islamic State attacked a big crowd of Christians in the city of Krasnogorsk...killing and wounding hundreds," the statement said.
The post also claimed the attackers "withdrew safely" after the attack.
IS has in the past claimed responsibility for attacks it did not carry out. U.S. intelligence officials, however, confirmed the claim shortly after the post.
Sources told CNN’s Alex Marquardt that there has been "fairly specific" intelligence that ISIS-K, also known as Islamic State – Khorasan Province, has been planning attacks inside Russia.
On March 7, the U.S. Embassy in Russia issued a warning that "extremists have imminent plans to target large gatherings in Moscow" and urged American citizens to stay away from concentrations of people over the next 48 hours.
And earlier this month, Russia's Federal Security Service (FSB) said it had thwarted an attack on a synagogue by an IS cell.
The attack on March 22 at the Crocus City Hall killed at least 40 and wounded more than 100, Russian state-controlled news agency TASS claimed, citing the preliminary data of Russia's Federal Security Service (FSB).
Images posted to social media showed them walking unchallenged through the venue and firing indiscriminately at those inside.