What is ISIS-K, the group that claims it carried out the Moscow concert attack?
ISIS-K is one of the most militant jihadist groups in the world, often mounting attacks against other Islamist groups, while also targeting Russia and the U.S.
The death toll from an attack on a concert hall in Moscow continues to rise. U.S. officials say they believe an organization known as ISIS-K, or the Islamic State Khorasan Province, carried out the strike. The group claimed responsibility on Friday, posting on the social media platform Telegram.
What is ISIS-K?
ISIS-K emerged in 2014 and 2015 in Afghanistan and neighboring Pakistan, after its leaders broke away from al-Qaida and the Taliban.
Its fighters declared loyalty to the even more violent and extremist Islamic State, also known as
