Editor's Note: This story contains descriptions of graphic scenes.
The Islamic State on March 23 released footage of the March 22 Crocus City Hall terrorist attack in a Moscow suburb.
The video was released through the Amaq News Agency, which is affiliated with the terrorist group.
Several gunmen opened fire at the Crocus City Hall in Krasnogorsk, a Moscow suburb, on the evening of March 22, killing at least 137 people and injuring at least 140, according to the latest updates by the Russian authorities.
The ISIS footage shows the gunmen recording themselves as they pursue people through the lobby of the Crocus City Hall, firing at them from close range with assault weapons.
The footage also shows a gunman stabbing a body lying on the floor with a knife several times.
At one juncture, one of the gunmen instructs another to “kill them and have no mercy."
The Islamic State previously claimed responsibility for the attack in a post on Telegram.
U.S. intelligence officials confirmed the claim shortly after the post.
The Russian authorities claimed a total of 11 people involved in the shooting have been detained, four of whom were called “the perpetrators.”
Later that day, Amaq published pictures of four men with covered faces allegedly involved in the terrorist attack, making their reliable identification difficult.
The Insider, a Russian independent investigative outlet, reported that the clothes of some of the men seem to match those of alleged perpetrators detained by Russian security services, based on the footage that appeared on Telegram.
The Kyiv Independent could not verify the claims.
Despite the Islamic State claiming responsibility for the attack, Russian officials are attempting to connect it to Kyiv without providing any evidence. Russian dictator Vladimir Putin has claimed that the detained suspects planned to flee to Ukraine.
Andrii Yusov, a spokesperson for Ukraine's military intelligence agency, refuted Russia's claims as an attempt to accuse Ukraine of involvement in the attack.
“The version that the perpetrators of the terrorist attack were fleeing toward Ukraine does not withstand any criticism,” Yusov told national television.
Two weeks before the attack, the U.S. Embassy in Russia issued a warning on March 7 that “extremists have imminent plans to target large gatherings in Moscow” and urged American citizens to stay away from crowded areas and venues over the next 48 hours. The U.K., Canada, Germany, and several other countries published similar statements soon after.
Ukraine's military intelligence (HUR) called the shooting a “deliberate provocation by Putin's special services.” HUR claimed the attack was intended to justify “even tougher” strikes on Ukraine and total mobilization in Russia.