MOSCOW, July 28./ITAR-TASS/. Pictures placed on Twitter by US ambassador to Kiev Geoffrey Pyatt, claiming to show weapons being fired on Ukrainian troops from Russian territory, are fake, a Russian official told ITAR-TASS.

Defense Ministry spokesman Igor Konashenkov said it was not accidental that the materials appeared on Twitter since it was impossible to establish whether they were authentic.

Low-resolution pictures made it unclear what was being shown and they could not be used as photographic evidence, the official said.

It was no secret that such fakes were being prepared by a group of American advisers working in the Ukrainian Security Service building in Kiev under the supervision of General Randy Kee, he added.

Earlier, Kiev officials repeatedly presented such pictures to justify the use of artillery and other heavy weapons by Ukrainian troops against civilians. Last Friday, Ukrainian Defence Minister Geletei once again unsuccessfully attempted to present such pictures in Ukrainian media as a sensation. On Sunday, it was the American ambassador who placed such satellite photos in the Internet, returning attention of loyal Ukrainian media to the theme.

Such a scheme is called an information carousel, the general said.

First, they present such disinformation in Ukrainian media to cause a reaction. Then, such "facts" are picked up by Washington officials. Then, Ukrainian media publish such materials as objective information, referring to State Department, Pentagon and White House officials. Afterwards, the real author of such fakes is practically lost, he added.