A tranche of declassified UFO files published online in 2015 by the CIA included one which tells a bizarre story about Russian troops killed in a deadly shoot-out with aliens in Siberia.The bizarre report claims that aliens attacked and killed 23 Russian troops after they fired a surface-to-air missile and brought down a low-flying saucer-shaped UFO.

Aliens in a UFO engaged Russian troops in a deadly shoot-out over Siberia

The weird CIA report, dated March 27, 1993, was one of a cache of previously classified UFO files published online by the CIA in 2015 after it was declassified in 2011.

The document was in fact a CIA translation of a report published by a Ukrainian newspaper Ternopil Vechirniy, the Daily Express reports.

According to the CIA document, after the dissolution of the USSR under the leadership of Mikhail Gorbachev in 1991, Western intelligence services obtained several previously classified KGB files. One of the files was a 250-page report detailing an alleged attack on Russian troops by aliens in a UFO shot down over Siberia.

The report claimed that a Russian military unit training in Siberia in 1987, spotted a low-flying saucer-shaped UFO and fired a surface-to-air missile at it. The missile hit the mysterious flying saucer UFO and brought it down. But after the UFO crashed to Earth, five short humanoid alien beings with large heads, large black eyes and spindly limbs climbed out of the wreckage.

Two soldiers who survived the deadly shoot-out said that after the strange-looking alien creatures emerged from the UFO debris, they held hands and merged into a brightly glowing spherical ball of white light that crackled threateningly.The mysterious ball of light then exploded, transforming 23 soldiers who stood watching into stone.

CIA official: 'Aliens possess weapons and technology that go beyond all human assumptions'

The corpses of the literally petrified soldiers were later taken to a secret Russian research facility where experts examined them. The experts concluded that the biological tissues of the soldiers were transformed in an instant into a substance with a molecular structure similar to limestone.

"If the KGB file corresponds to reality, this is an extremely menacing case," a CIA official commenting on the incident said, according to the translated report. "The aliens possess such weapons and technology that go beyond all our assumptions."

'Be careful about what the CIA publishes online, it could be disinformation,' a skeptic warns

It is unknown why CIA officials decided to file a translation of an unverified report by a Ukrainian newspaper among its cache of classified UFO files. But skeptics have speculated about the reason, with some suggesting that the CIA officials who filed the report might have taken it seriously. Others suggested that the decision to declassify the report and publish it might have been part of widely alleged government disinformation campaign efforts.

But some skeptics suggested that the CIA might have released the file after it emerged that the Ukrainian newspaper had sourced the report from the Canadian Weekly World News, known for publishing outlandish and sometimes entirely fictitious reports.

"You have to be careful about what the CIA publishes online, as it could be misinformation," a YouTube user cautioned.