Watch: Ukraine Choppers Enter Russian Airspace, Strike Fuel Depot

Ukraine attacked a fuel storage depot in western Russia earlier this week, the first reported strike by a manned aircraft by Kyiv on Russian soil. Videos showed helicopters firing several rockets at a fuel storage depot in Russia's Belgorod, followed by an explosion.

The strike, carried out by Mi-24 choppers, is believed to be the first time Russia has reported a manned airstrike on its territory since the Korean war in the 1950s.

Security camera footage of the depot showed a flash of light from what appeared to be a rocket fired from a low altitude in the sky, followed by an explosion on the ground.

"There was a fire at the petrol depot because of an airstrike carried out by two Ukrainian army helicopters, which entered Russian territory at a low altitude," Belgorod region governor Vyacheslav Gladkov wrote on messaging app Telegram.

Two employees at the storage facility were injured in the fire, he said.

Ukraine said it could neither confirm nor deny responsibility for the huge fire at the fuel depot in Belgorod.

Belgorod lies around 80 kilometres from the Ukrainian city of Kharkiv, which has been pummelled by Russian forces since Moscow sent troops to Ukraine on February 24. The city has served as a logistics hub for Russian troops fighting in nearby eastern Ukraine.