A fiery explosion has rocked a Russian fuel depot near the border – with Moscow claiming Ukraine had attacked the facility, but Kyiv denied any involvement.

Regional Governor Vyacheslav Gladkov said two Ukrainian helicopter gunships had flown at low altitude and struck the facility in the city of Belgorod north of the border, triggering the blast and fire.

Two workers at the depot were injured, he said. But Russian media cited a statement from state oil company Rosneft that denied anyone was hurt.

More than 300 firefighters battled the blaze, using a helicopter and a special firefighting train, the Belgorod mayor’s office said.

Mr Gladkov said he met with residents who were moved from their homes to a nearby sports facility. He also posted photos of craters and metal fragments in a rural area where he said explosions had damaged a power line and broken a window.

It would not be the first attack reported inside Russia since the war began on February 24, although there has been nothing as spectacular.

Oleksiy Danilov, secretary of Ukraine’s national security council, denied that Ukraine was responsible.

“For some reason, they say that we did it, but in fact this does not correspond with reality,” he said on Ukrainian television.

(PA Graphics)

Earlier, presidential adviser Oleksiy Arestovich said: “We are carrying out defensive operations on our territory. Russian authorities bear responsibility for everything that happens at Russian territory.”

Russian authorities “must figure out what’s going on in Belgorod,” he said.

“Maybe someone smoked in the wrong place. Maybe there was something else. Maybe Russian troops are sabotaging orders and don’t want to enter Ukrainian territory by available means.”

Any airborne attack inside Russia would likely require skilful flying to avoid its air defences.

The explosion drew a muted response from the Kremlin, with spokesman Dmitry Peskov saying it was not helpful for talks with Ukraine.

On Russian social media, some users expressed surprise that Ukraine was still capable of mounting such an attack or getting past Russian air defences.

Russia Ukraine War
Ukrainian army soldiers take part in a military sweep (Rodrigo Abd/AP)

Russia’s daily video briefings from the Defence Ministry often stress the number of Ukrainian planes and helicopters shot down or destroyed.

Belgorod is about 16 miles from the border and is roughly opposite Kharkiv, Ukraine’s second-largest city which has been under Russian bombardment since the early stages of the war.

Earlier incidents in the Belgorod region had caused alarm locally but had little wider resonance in the context of the war, which Russia portrays as a “special military operation” with little effect on the lives of ordinary citizens.

On the first day of the war, three people were reported injured from shelling in Belgorod, although there was no independent confirmation.

A statement from Russia’s state Investigative Committee said two adults and one child were injured, and an attempted murder probe was launched.

Another criminal investigation by the committee was opened on March 1 after a report that two Ukrainian missiles from an Uragan launcher had landed in a rural area. That report also was not independently confirmed.

Mr Gladkov said last week that a shell fired from Ukraine had exploded in a village in the Belgorod region in an incident in which the Russian Orthodox Church said had killed a military chaplain.

A similar incident was reported to have damaged houses. There was no independent confirmation of those reports.

Other explosions on March 29 were due to what Mr Gladkov said he had heard was a fire at a munitions store in the border village of Krasny Oktyabr, citing “unverified information”.

Ukraine was not blamed for the incident and Mr Gladkov said he was awaiting official comment from the Defence Ministry, although none followed and the cause of the fire remained unclear.