The head of Ukrainian Defense Intelligence, Kyrylo Budanov, said that drone attacks earlier this week on a Russian air base in Pskov were launched from within Russian territory.

Budanov told the online publication WarZone: "We are operating from Russian territory; four Russian IL-76 military transport planes were hit as a result of the attack."

"Two were destroyed and two were seriously damaged," Budanov said.

Satellite imagery shows that two Il-76s — the aircraft that forms the backbone of Russian military airlift — were destroyed, and two appear to have damaged fuselages.

"The fuel tanks and an important part of the wing spar located in the upper part of the IL-76 were targeted," Budanov said.However, he declined to tell WarZone what type of drones and how many were used in what was one of Ukraine's most ambitious aerial attacks inside Russia.

Pskov is about 800 kilometers (roughly 500 miles) from the Ukrainian border in northwestern Russia near Estonia.

The Kremlin declined to comment on the claim Friday, with spokesperson Dmitry Peskov deferring questions to the Russian defense ministry.