Anatoly Antonov
© AP Photo/Patrick SemanskyRussian ambassador to the United States Anatoly Antonov.
The US has dismantled its counterterrorism cooperation with Moscow, Russian Ambassador in Washington DC Anatoly Antonov has claimed. The diplomat added that joint work in this field had been among the key aspects of the partnership between the two nations.

The official's remark came shortly after several gunmen staged one of the deadliest terrorist attacks in Russia's modern history, unleashing a shooting spree at the Crocus City concert hall just outside of Moscow on Friday evening. According to the latest estimates, the raid has claimed the lives of at least 133 people, with scores more injured.

Earlier this month, the US embassy in Moscow warned its citizens against attending large gatherings due to an imminent threat of a terrorist attack in the Russian capital.

In an article on Sunday, RIA Novosti quoted Antonov as saying: "I've always reminded the Americans that our president [Vladimir Putin] was the first one to extend a hand to the Americans and stated readiness to provide assistance in 2001," referring to the September 11 terrorist attacks.

He noted that "some things [in this cooperation] worked out... and it is all destroyed today through no fault of our own."

In its March 7 alert, the US embassy said that it was "monitoring reports that extremists have imminent plans to target large gatherings in Moscow, to include concerts." The embassy called on Americans to stay vigilant and "monitor local media for updates."

The embassies of several other nations followed suit.

Speaking to reporters hours after the terrorists attacked the Moscow concert venue, White House National Security Council spokesperson John Kirby pointed out that the warning earlier this month was not "related to this specific attack."

"I'm not aware of any advance knowledge that we had of this," the official added.

On Saturday, Russia's FSB domestic security service reported that it had detained 11 suspects in connection with the attack. The four presumed perpetrators were intercepted in Bryansk Region, not far from the Ukrainian border.