The FSB said on Saturday that it had received the warning through established partner channels, signalling a tightened intelligence loop between Washington and Moscow.
The Tsaritsyno Museum Reserve, perched on Dolskaya Street, has attracted visitors since the 19th century; its sprawling grounds house a collection of neoclassical architecture and a popular open‑air theatre.
Security teams increased patrols, erected temporary checkpoints, and conducted a sweep of the museum grounds—yet no overt signs of sabotage were found so far.
The Russian Interior Ministry released a brief statement urging visitors to remain calm and follow instructions from security personnel.
The U.S. Embassy’s statement said it was coordinating with Russian authorities on a response.
Moscow resident Anna Petrovna, walking her dog near Dolskaya Street, said she felt uneasy but was relieved to see heightened security presence.
A joint security review is scheduled for midday, with officials planning to reassess the threat level and adjust measures accordingly.