Russia accused Ukraine of carrying out an air strike against a fuel depot in the Russian city of Belgorod on Friday, an incident the Kremlin said could affect peace talks, but a top Kyiv security official denied responsibility.

Russia's defence ministry said two Ukrainian helicopters struck the facility in Belgorod, some 35 km (22 miles) from the border with Ukraine, after entering Russia at extremely low altitude at around 5 a.m. Moscow time (0200 GMT).

The resulting blaze forced the evacuation of some people but late in the day Belgorod mayor Anton Ivanov said fire services were extinguishing the last remnants.

"There is no threat to human life and health. All residents can return to their homes," he said in an online post.

Ukraine's top security official rebuffed the Russian accusation - the first by Moscow of an air strike on Russian soil since Moscow launched its invasion on Feb. 24. Belgorod is one of Russia's main logistics hubs for the war.

"For some reason they say that we did it, but according to our information this does not correspond to reality," said Security Council Secretary Oleksiy Danilov.

Earlier, defence ministry spokesman Oleksandr Motuzyanyk said he would neither confirm nor deny a Ukrainian role.

"Ukraine is currently conducting a defensive operation against Russian aggression on the territory of Ukraine, and this does not mean that Ukraine is responsible for every catastrophe on Russia's territory," he said.

The White House had no comment on Kremlin allegations that Ukraine had bombed the depot, press secretary Jen Psaki said.

Kremlin spokesman Dmitry Peskov said President Vladimir Putin had been briefed about the incident. Peskov said the strike could jeopardise Moscow's peace negotiations with Kyiv.

Ukraine's Danilov retorted: "He says it doesn't help talks, but does it help talks when they kill our children, our women - these outrages they commit on our land? These people are kind of sick."

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

Regional governor Vyacheslav Gladkov said the resulting blaze injured two workers.

In an online post, Gladkov said a second blast damaged a power line near the village of Nikolskoye but that no one was hurt. Pictures he posted showed a crater in a field.

Russian oil firm Rosneft, which owns the fuel depot, said no one was hurt in the fire. Russia's defence ministry said the facility was exclusively for civilian use.

An ammunition depot near Belgorod caught fire on Wednesday, causing a series of blasts. At the time, Gladkov said authorities were waiting for the defence ministry to establish its cause.

Moscow calls its intervention in Ukraine a "special military operation."