Just prior to the scheduled performance of a Russian rock band Picnic, men wearing camouflage attire began to indiscriminately fire from machine guns towards attenders inside Crocus City Hall located in Krasnogorsk, a city in close proximity of Moscow. The terrorists ignited a flammable liquid, causing a fire in the Crocus City Hall. Victims died of gunshots as well as poison from the liquid.
The terrorist attack killed over 150 people and is the deadliest in all of Russia’s history since the Beslan School Siege of 2004.
The attack has been claimed by Islamic State’s Khurasan Province, which is an emerging global terrorist threat among the Salafi jihadist groups. A few days before the massacre, 2 alleged members of IS-KP have been arrested by German authorities by revealing a plot. Prosecutors say that the two suspects intended to use firearms to kill police officers and other people in the vicinity of the Swedish Parliament in Stockholm.
United States embassy in Russia warned of a terrorist attack prior, in accordance with the "duty to warn" mandate of the US intelligence community, the US also privately alerted Russian officials to the possibility of an imminent attack by IS-KP based on intelligence obtained earlier in March.
Vladimir Putin referred to the warnings as "outright blackmail and an intention to intimidate and destabilize our society", refusing to take any security measures before the deadly attack.