US Embassy warns of credible mass casualty threat at Tsaritsyno Museum Reserve in Moscow

The embassy warning

On Saturday, 31 October 2026, the US Embassy in Moscow said it was aware of a credible threat of a mass casualty event at the Tsaritsyno Museum Reserve, a palace and park complex in southern Moscow. The embassy posted the warning on X and on its website, and it dated the threat to that same day. The notice gave the reserve's address as Dolskaya Ulitsa 1 and did not specify the nature of the threat. The wording stressed that the threat applied to 31 October itself, and the embassy said Washington was working with Russian authorities on a response.

“The U.S. government is coordinating with appropriate Russian authorities on a response.”

Advice to the public

The embassy told people to avoid the reserve and crowded places, to stay alert and to be aware of their surroundings. Its recommendations included reviewing a personal security plan, keeping a mobile phone charged for emergencies, carrying valid identification and following local media for further information. It also urged people to enrol in the Smart Traveler Enrollment Program (STEP) to receive health and security updates. The guidance was tied specifically to 31 October 2026, and the notice gave no time of day for the threat.

Russian security response

Russia's Federal Security Service (FSB) told the state news agency TASS that it had received information from American partners about preparations for a possible terrorist attack in Moscow. The service said appropriate measures were being taken in response. The embassy notice came only days after Russian Foreign Ministry spokeswoman Maria Zakharova, speaking on 28 October, accused Ukrainian President Volodymyr Zelensky of trying to sabotage efforts to settle the conflict in Ukraine, Ziare.com reported. Russia and the United States have been pursuing diplomatic efforts to resume consultations on that conflict.

A precedent in 2024

The US Embassy had issued a similar warning before the April 2024 attack on Crocus City Hall, a concert venue on the edge of Moscow. Citing unnamed American officials, The Washington Post reported that Washington passed threat information to the FSB on 6 March 2024, and Deutsche Welle relayed that reporting. The embassy published its own warning on 7 March 2024, saying it was tracking reports that extremists planned to attack large gatherings in Moscow, including concerts. US citizens were advised to avoid large crowds for 48 hours.

What the reporting does not yet show

No attack, casualties or arrests are reported in the articles reviewed. Rzeczpospolita describes Tsaritsyno as an 18th-century palace and park complex built for Empress Catherine the Great, covering more than 400 hectares of green space in southern Moscow. Ziare.com adds that the palace was renovated in the 2000s and is now a popular leisure destination for Muscovites. Neither outlet links the site to the threat itself, and the embassy did not say what form an attack might take. Further official detail had not appeared in the reports reviewed.