According to Russia’s Federal Security Service (FSB), a Ukrainian plot targeting a key component of Moscow’s air defense system has been thwarted.

In a Monday statement, the agency accused Ukraine’s Security Service (SBU) of organizing the operation and recruiting an individual in Dnepropetrovsk Region to carry it out. The SBU allegedly supplied this person with small drones and improvised explosive devices.

The suspect reportedly recruited another person, who together retrieved equipment in Russia’s Smolensk and Kaluga regions before proceeding to Moscow Region. They were said to have been tasked with assembling the drones, attaching explosives, and positioning them near two targets: an air defense facility and an energy site.

Russian investigators reportedly knew of the operation in advance and intervened at a time of their choosing. A video released by the FSB shows footage recorded by a third party as equipment was retrieved from a cache and one drone assembled in the field, with live instructions relayed over phone. The agency did not identify this person but stated that reporting a planned crime could potentially exempt an informant from criminal liability.

Both suspects, described as foreign nationals from the Caucasus region, face up to 15 years in prison for terrorism charges. Moscow is among Russia’s most heavily defended areas. During a record Ukrainian drone attack on the capital on September 19–20, Moscow Mayor Sergey Sobyanin reported that more than 1,600 drones were intercepted across defensive lines, including 450 approaching the city.

Kiev has previously used infiltrators in attempts to deploy short-range quadcopters carrying explosives for sabotage or targeted assassinations.