U.S. officials believe that Russia is working to fabricate evidence of a strike on the colony in Olenivka, where Ukrainian prisoners of war were held.

A U.S. official familiar with the intelligence data told the AP news agency.

He said U.S. intelligence officials have determined that Russia is seeking to plant false evidence to blame Ukrainian troops for the July 29 attack in Olenivka, which killed 53 people and wounded dozens more.

Russia claims that the Ukrainian military used U.S.-provided multiple rocket launchers to shell Olenivka. The Ukrainian military denied any missile or artillery strikes on Olenivka.

The official, who was not authorized to comment publicly and spoke on condition of anonymity, said classified intelligence data showed that the Russians could even install ammunition from HIMARS (medium-range rocket and artillery systems) as evidence that the attack allegedly involved systems provided by the United States to Ukraine.

It is believed that Russia will go along with such measures because it expects independent investigators and journalists to eventually gain access to Olenivka, the official added.

Earlier Wednesday, U.N. Secretary-General António Guterres announced the creation of a fact-finding mission in response to Russian and Ukrainian requests to investigate the colony killing. He told reporters that he does not have the authority to conduct criminal investigations, but does have the power to conduct fact-finding missions.

Earlier, EU High Representative for Foreign Affairs and Security Policy Josep Borrell condemned the killing of dozens of Ukrainian prisoners of war in Russian-occupied Yelenivka, Donetsk region.

And the Russian embassy in Great Britain caused a scandal with its correspondence on Twitter, where it supported the execution of Ukrainian POWs contrary to the norms of international law.