CNN reported this with reference to sources familiar with US intelligence, according to Ukrinform.
According to the publication, US officials believe these pro-Ukrainian agents inside Russia carried out a drone attack that targeted the Kremlin in early May by launching drones from within Russia rather than flying them from Ukraine into Moscow.
It is not clear whether other drone attacks carried out in recent days – including one targeting a residential neighborhood near Moscow and another strike on oil refineries in southern Russia – were also launched from inside Russia or conducted by this network of pro-Ukrainian operatives.
But US officials believe that Ukraine has developed sabotage cells inside Russia made up of a mix of pro-Ukrainian sympathizers and operatives well-trained in this kind of warfare. Ukraine is believed to have provided them with Ukrainian-made drones, and two US officials told CNN there is no evidence that any of the drone strikes have been conducted using US-provided drones.
Officials could not say conclusively how Ukraine has managed to get the drones behind enemy lines, but two of the sources told CNN that it has established well-practiced smuggling routes that could be used to send drones or drone components into Russia where they could then be assembled.
Who exactly is controlling these assets is also murky, the sources told CNN, though US officials believe that elements within Ukraine’s intelligence community are involved.
Ukrainian President Volodymyr Zelensky has set general parameters for what his intelligence and security services are allowed to do, two of the sources said, but not every operation requires his sign-off.
As reported, according to Russian media, Moscow and the Moscow region were attacked by about 25 drones, most of them were shot down by air defense forces in the Moscow region, some of the drones hit trees and wires as they were flying at very low altitudes. Three drones crashed into residential buildings, but one of them failed to detonate its explosives.
Russia's Investigative Committee said that its investigators were investigating on location "the facts of the fall of unmanned aerial vehicles on houses in Moscow".