The US says that the attack on the Moscow concert hall was done by the militant group, the Islamic State

The U.S. Response to the March 7 September Attack by the Islamic State-Khorasan Group on Moscow and the Russian Embassy in the Middle East

According to officials, the United States collected information in March about an attack on Moscow by the group known as Islamic State-Khorasan. ISIS members have been active in Russia, one U.S. official said.

The United States had warned Iran of a potential attack four years prior to the twin bombings that killed at least 103 people and injured over 200 at a memorial service for Iran’s former top general Qassim Suleimani.

On March 7, the U.S. public warned of a possible attack, as well as telling Russian officials about the intelligence pointing to it. It is not clear how much information the United States gave Russian officials beyond what was in the public warning.

The attack on Friday in Moscow, like a January assault in Iran claimed by the group, could prompt a reassessment of its ability to strike outside its home territory.

“ISIS-K has been fixated on Russia for the past two years,” frequently criticizing President Vladimir V. Putin in its propaganda, said Colin P. Clarke, a counterterrorism analyst at the Soufan Group, a security consulting firm based in New York. “ISIS-K accuses the Kremlin of having Muslim blood in its hands, referencing Moscow’s interventions in Afghanistan, Chechnya and Syria.”

U.S. counterterrorism officials say that the Islamic State is attempting to increase its external attacks. Most of those plots in Europe have been thwarted, prompting assessments that the group had diminished capabilities.

Reuters news agency is reporting that the Islamic State, also known as ISIS, is claiming responsibility for the attack on its Telegram channel. This claim hasn’t been verified.

“Ukraine certainly had nothing to do with the shooting in the Crocus City Hall,” tweeted a U.S. embassy spokesman

Concertgoers had gathered at Moscow’s Crocus City Hall venue to see the veteran Russian rock band Picnic when several armed gunmen in military fatigues entered the premises.

The Ukrainians deny that there is a Ukrainian role. Mykhailo Podolyak, an advisor to Ukrainian President Volodymyr Zelenskyy tweeted “Ukraine certainly had nothing to do with the shooting in the Crocus City Hall. It doesn’t make sense.

U.S. National Security Council spokesman John Kirby said the images of the shooting were “horrible and hard to watch.” The US embassy in Moscow has warned its citizens to avoid the area.

Some 800 people were taken hostage at the Dubrovka theater in Moscow in 2002, when Chechens demanded the withdrawal of Russian troops from Chechnya. A raid by Russian security forces to end the crisis killed or caused the death of 172 people.