A Russian official blamed a Ukrainian airstrike for a blast at an oil depot in the city of Belgorod on Friday. If confirmed, it would be the first attack of its kind since Russia's invasion of Ukraine on Feb. 24.
Vyacheslav Gladkov, the governor of Belgorod, which is close to the Ukrainian border, said a fire at the depot was the result of “an airstrike from two helicopters of the armed forces of Ukraine."
Nobody was killed or injured, he added in a statement on his official Telegram channel.
Ukrainian Foreign Minister Dmytro Kuleba would not comment on his country's involvement in the incident.
“I can neither confirm nor reject the claim that Ukraine was involved in this simply because I do not possess all the military information,” Kuleba said in response to reporters’ questions.
The Ukrainian Ministry of Defense did not respond to NBC News’ requests for comment.
NBC News could not independently verify the claim the Ukrainian armed forces were responsible. Footage verified by NBC News showed a large fire and plumes of black smoke at the oil and natural gas fuel depot in Belgorod.
The allegation, the first time Russia has accused Ukrainian forces of launching an air strike on Russian soil, follows warnings from Western powers that Moscow may stage “false flag” attacks to justify launching or escalating the conflict.
U.K.-based military analyst Joseph Dempsey analyzed videos of the alleged attack, and concluded that a Russian-made Hind variant of the Mil Mi-24 helicopter gunship was involved.
It was “unclear” whether the helicopter was operated by Ukrainian or Russian forces, added Dempsey, who is a research associate at the International Institute for Strategic Studies, a London-based think tank.
The munitions which appeared to have been used, particularly unguided rockets, “are primarily of Soviet origin and remain in use with both Russia and Ukraine,” he added.
Ukrainian forces are “capable of launching such an attack,” according to David Jordan, the director of the Freeman Air and Space Institute at King’s College London. “They have helicopter crews who are pretty competent and would be able to do this,” he said.
He added that without a proper assessment it was hard to work out exactly what happened, “but if the damage was pretty serious to an important part of the facility then that would more likely point to it being a Ukrainian attack.”
If it turned out the damage was minimal, he said that might point to it being a Russian false-flag operation, although he stressed it was “too early to judge.”
He added that even if it was the only operation the Ukrainians had planned, Moscow “would now have to be prepared for further attacks.”
Russia, meanwhile, showed support for ongoing peace talks with Ukraine, with Foreign Minister Sergey Lavrov saying during a visit to India that they “inevitably” had to continue.
Ukraine and Russia resumed peace talks on Friday in an online format, according to Ukrainian officials.