https://web.archive.org/web/20240322225756/https://www.nytimes.com/2024/03/22/world/europe/isis-moscow-attack-concert-hall.html
On 19 March, Putin said the U.S. embassy’s warning “resembles outright blackmail and an intention to intimidate and destabilize our society.”
The Islamic State – Khorasan Province (IS–KP), a South-Central Asia-based regional affiliate of the Islamic State, claimed responsibility in a statement through the Amaq News Agency shortly after the attack.