US Embassy warns of mass casualty threat at Moscow museum

The US Embassy in Moscow issued a security alert on Saturday warning of a credible threat of a mass casualty event today, October 31, at the Tsaritsyno Museum Reserve, and Russia's FSB said it had received information from the United States about preparations for a terrorist attack in Moscow and was taking measures.

Why it matters: The warning names a specific site and day, and Moscow has publicly confirmed receiving the US information through partner channels, which makes this a live US-Russia security channel operating in the open even as the two governments remain on opposite sides of the Ukraine war.

Data as of US Embassy in Moscow security alert of October 31, 2026, issued by U.S. Mission Russia and read in full in this run via the live browser after a direct text fetch returned an access error; the alert's wording here is the embassy's own. Fox News and Clash Report reporting of the same alert was also read in full in this run. The FSB statement is Russia's own, as reported by RIA Novosti and carried by Reuters syndication and Clash Report, read in full in this run. The FSB did not mention Tsaritsyno or say when or where an attack is planned, and no incident at the site had been reported at check time.

The US Embassy in Moscow said on Saturday that it is aware of a credible threat of a mass casualty event today, October 31, at the Tsaritsyno Museum Reserve at Dolskaya Ulitsa 1, that the US government is coordinating with Russian authorities on a response, and that Americans should avoid the location today, stay alert and avoid crowds, keep phones charged, carry identification, review their personal security plans, monitor local media and enroll in the State Department’s Smart Traveler Enrollment Program. Russia’s Federal Security Service said it had received information from the American side through partner channels about preparations for a terrorist attack in Moscow and that relevant work is being carried out, though it did not mention Tsaritsyno, describe the information, or say when or where an attack is planned. The museum reserve told the Telegram channel Mash it had no information about a threat and was operating as usual, and no incident at the site had been reported at check time.

US Embassy warns of mass casualty threat at Moscow museum

Sources