Ukrainedealt a new, expensive blow to Russia as its special security forces claim they have downed two military aircraft. The Security Service of Ukraine (SBU) shared on Friday evening details of the successful operation.

In a message shared on the social media messaging platform Telegram, the SBU claimed: "The SBU and the SSO [Special Operations Forces] of the Armed Forces of Ukraine destroyed two Russian SU-34 aircraft at the Marynivka airfield in the Volgograd region, damaged two more." This was the result of a joint special operation, the SBU explained, without sharing when the attack was carried out. Each Russian Su-34 aircraft reportedly costs around £23million.

Alongside the economic blow for Russia, the reported downing of these planes also helps weaken the presence on the frontline of Russian jets.

The SBU's message continued: "The enemy actively uses these multifunctional fighters on the front line for bombing, including for dropping KABs."

The Ukrainian attack was carried out using drones - a relatively cheap but increasingly effective weapon embraced by Kyiv's military forces.

The message read: "The SSO of the Armed Forces of Ukraine and the SBU worked on the Russian fighters using long-range drones. The attacks also caused a fire in the technical and operational part of the enemy airfield, which is a critically important infrastructure of the military facility. It is there that the enemy prepares the aircraft for flights, carries out their current maintenance and repair work. Together with our brothers, we continue to work on weakening the aviation component of the Russian army. Military airfields and aircraft deep behind enemy lines are a completely legitimate target for Ukraine!"

Ukraine rarely comments on attacks launched beyond its internationally recognised borders, which include the Crimean peninsula, illegally annexed by Russia in 2014.

News of the attack comes hours after, on June 26, Ukrainian Defence Minister Rustem Umerov announced the decision to "scale up" the number of long-range strikes into the Russian territory.

Umerov told the Kyiv Post: "About two weeks ago, a decision was made to scale up these operations. We are already preparing a new large contract to increase the intensity of strikes."