The Russian ministry of defence was distributing false images it claimed were from recent American operations in Syria, but which in fact show scenes from a computer game and an old Iraqi military video.
The images, shared on the ministry's official Facebook and Twitter pages, are accompanied by a caption describing the pictures as an Islamic State convoy leaving the Syrian city of Abu Kamal, dated November 9 2017.
Russia claimed these pictures showed "irrefutable evidence" that the US-led coalition was working together with Isis troops "to promote American interests" in the Middle East.
BellingCat.com said eagle-eyed Twitter users immediately spotted some problems with the images.
"One image claimed to show an ISIS convoy leaving Abu Kamel on November 9th, 2017. What this in fact showed was a cropped screenshot from the mobile phone game AC-130 Gunship Simulator, specifically a screenshot from a promo video for the game," it said.
The Kremlin later defended the images, calling the social media posts a "mistake" by a civilian contractor.
Dmitry Peskov, spokesman for Russian President Vladimir Putin, said on Wednesday that "mistakes happen", adding that the pictures were quickly removed from social media and the contractor had been "penalised", according to Russian News Agency TASS.