Did the United States have prior knowledge of the Moscow terrorist attack?

　　China News Service, March 23 (Xinhua) On the evening of the 22nd local time, a shooting occurred at a concert hall in the suburbs of Moscow, the Russian capital, resulting in at least 115 deaths and over 100 injuries. Prior to this, the U.S. Embassy in Russia issued a warning on the 7th that it had detected that "extremists" were plotting to launch an attack in Moscow in the next few days.

According to a report by RIA Novosti on the 23rd local time, the Russian Investigative Committee stated that a terrorist attack occurred at a concert hall in the suburbs of Moscow on the 22nd. The death toll has now risen to 115. The picture shows the concert hall that was attacked and burned beyond recognition after the fire.

　　The U.S. Embassy issued a message at the time saying, "The (U.S.) Embassy is monitoring information about extremists planning to launch attacks on large gatherings (including concerts) in Moscow, and advises U.S. citizens to avoid attending large gatherings in the next 48 hours."

　　The U.S. Embassy in Russia also reminded American citizens to "avoid crowds, pay attention to local media news, and pay attention to the surrounding environment."

　　The New York Times quoted people familiar with the matter as saying that this warning was related to the attack in Moscow on the 22nd.

　　According to TASS news agency, after the attack on the 22nd, John Kirby, the strategic communications coordinator of the White House National Security Council, also talked about the previous warnings issued by the United States when answering questions. However, he said that the U.S. government "had no advance information about the attack on the concert hall."

　　A source in the Russian intelligence service confirmed that the United States provided Russia with early warning of terrorist attacks. The source said that the United States provided information about possible attacks to Russian intelligence services, but the information was relatively general and lacked specific content.

　　According to CNN, the extremist organization "Islamic State" claimed responsibility for the attack on a concert hall near Moscow, but the organization did not provide evidence to support this claim.

　　Subsequently, the Russian media "Russia Today" pointed out: There is currently no official news confirming that the "Islamic State" was responsible for the shooting incident in Moscow, and the relevant information from the US media has not been verified.