KIEV, September 24. /ITAR-TASS/. Accusations that Ukraine's National Guard was responsible for killing civilians and burying bodies in the embattled south-east regions have been denied by the country's National Security and Defense Council.

They are "a well-planned but rather badly thought-out provocation,” spokesman Andriy Lysenko said a day after militia forces of the self-proclaimed Donetsk People’s Republic found a burial site on the territory of a local mine 60 kilometres from the city of Donetsk.

Four bodies, one of them beheaded, had been recovered, militia said, specifying that units of Ukraine’s National Guard had been stationed there earlier.

Russia’s Investigative Committee said on Wednesday it would probe the killings during criminal inquiries into the war in the country's south-east.

“Reports about killings of civilians whose bodies were found in a mass grave on the outskirts of Donetsk will be thoroughly investigated by the Main Investigative Department of the Investigative Committee within the criminal case on use of banned methods and tactics of warfare against civilians in Ukraine’s south-east,” committee spokesman Vladimir Markin said.

Russia's Foreign Ministry plans to engage international organizations, including the United Nations, the Organization for Security and Co-operation in Europe and the Council of Europe, in investigating circumstances of the burial site, ministry human rights ombudsman Konstantin Dolgov told the civic committee for support of Ukraine’s south-east in the Federation Council.