[HIGHLIGHTS] What is ISIS-K, the terrorist group linked to the devastating Moscow concert hall attack?

ISIS-K is believed to be active in Afghanistan, Pakistan and Iran, and appears to have aspirations to attack Europe and the United States, according to intelligence officials. ISIS-K was also responsible for the 2021 attack at the Abbey Gate, in front of Kabul's Hamid Karzai International Airport, in which 13 US service members and 170 Afghan civilians were killed.

U.S. officials warned both Iran and Russia that ISIS-k was prepared to attack in those countries before the attacks occurred.