Ukraine has created a network of agents and supporters in Russia who are involved in sabotage and provides them with drones.
Source. This was reported by CNN, citing sources familiar with US intelligence.
US officials believe that these pro-Ukrainian agents inside Russia carried out a drone attack on the Kremlin in early May, launching drones from Russian territory.
Ukraine is believed to be providing its agents with Ukrainian-made drones – two U.S. officials told CNN that the U.S. has no evidence that the attacks were carried out with U.S. weapons.
U.S. officials were unable to say exactly how Ukraine managed to get the drones behind the front lines, but two sources told CNN that it had established well-established smuggling routes that could be used to send the drones or their components to Russia.
The European intelligence official noted that the Russia-Ukraine border is large and difficult to control, making it suitable for smuggling.
"This is a peripheral area of Russia. Survival is everyone's problem, so cash works wonders," the source said.
It is unclear who exactly is controlling this work, but CNN sources say that the "Ukrainian intelligence community" may be behind it.
According to two CNN sources, Ukrainian President Volodymyr Zelenskyy has set general parameters for what intelligence and security services are allowed to do, but not every operation requires his approval.
A spokesman for the head of the SBU told CNN that the mysterious explosions and drone strikes in Russia will continue.
Publicly, US officials condemn Ukraine's strikes on Russian territory. But in private conversations with CNN, U.S. and Western officials have said they consider such strikes a "smart military strategy" that can divert Russian resources to defend its own territory.
"The Russian command is now facing an acute dilemma – whether to strengthen its defenses in the border regions of Russia or to strengthen its borders in occupied Ukraine," a new British intelligence report says.
Background. As ISW has previously reported, Putin is trying to downplay the significance of the drone attack on Moscow – the Kremlin is afraid to reveal the limited options it has to take revenge on Ukraine.