US Embassy Warns of 'Credible Threat' of Mass Casualty Event at Moscow's Tsaritsyno Park on Oct. 31

The U.S. Embassy in Moscow issued a security alert Saturday, Oct. 31, warning of "a credible threat of a mass casualty event TODAY October 31, at the Tsaritsyno Museum Reserve in Moscow at Dolskaya Ulitsa 1." The embassy said the U.S. government is "coordinating with appropriate Russian authorities on a response."

The alert does not say who is behind the threat. It does not describe the method of any planned attack.

What the embassy told Americans to do

The embassy told U.S. citizens to avoid the Tsaritsyno grounds on Oct. 31, stay away from crowds, and keep their phones charged. It also advised them to review personal security plans, carry proper identification and monitor local media for updates.

Tsaritsyno is a palace and park complex in southern Moscow, about 16 kilometers (10 miles) from the Kremlin. It was founded in 1775 as a summer residence for Empress Catherine II. Moscow's deputy mayor Natalya Sergunina said in 2023 that the museum drew more than two million visitors in 2022. Another outlet, Kursiv, puts annual attendance at around seven million, so the figures conflict. The surrounding grounds, used daily by Muscovites for exercise and dog walking, see even more foot traffic, according to The Art Newspaper.

Russia's response

Russia's Federal Security Service confirmed it got the warning. "We have received information from U.S. partners regarding plans for a terrorist attack in Moscow. We are taking appropriate action," the FSB told state media. The agency also said "relevant work is underway," according to TASS and Interfax, and that the tip came through partner channels.

The Tsaritsyno park administration told the Telegram channel Mash that the complex was operating as normal.

The Crocus City Hall precedent

The warning lands in the shadow of March 22, 2024. Gunmen attacked the Crocus City Hall concert venue outside Moscow, opened fire on the crowd and set the building ablaze. Russian investigators reported 149 people killed and 609 injured. A faction of the Islamic State claimed responsibility.

Washington had warned Moscow beforehand. Russian foreign intelligence chief Sergei Naryshkin later said the FSB had received information from U.S. intelligence that an attack was possible, but that it was "too general and did not allow us to fully identify those who committed this terrible crime."

This time the embassy has named a specific site and a specific date, which is more than Naryshkin said Moscow had in 2024.

Russian officials, including President Vladimir Putin, have also repeatedly alleged that Ukraine played a role in Crocus. They have offered no evidence. Kyiv has strongly denied any involvement.

War backdrop

The alert came as the war grinds on. On Friday, Ukraine struck an oil refinery in southern Russia, ending a two-week pause on energy infrastructure attacks that President Donald Trump had brokered. The day before, Russian drone and missile strikes in Ukraine killed at least 27 civilians, according to the Wall Street Journal.

No source has connected the Tsaritsyno threat to either development. The embassy has not said who it believes is responsible, and the FSB referred only to a "terrorist attack."

A thin diplomatic footprint

The embassy's own website notes that the U.S. consulates in Vladivostok and Yekaterinburg remain suspended "due to critically low staffing" of the U.S. Mission to Russia. The embassy in Moscow continues to provide routine and emergency services to U.S. citizens. It listed +7 495 728-5577 and MoscowACS@state.gov for help.

What remains open

What happens at Tsaritsyno today is the immediate concern. The FSB has said it is acting, but it has not said whether it will close the park, make arrests or release details. Neither government has said what the underlying intelligence is or how it was obtained.

The embassy has said only that it will keep coordinating with Russian authorities and that Americans should follow local media for further information.