A rumor has appeared on social media suggesting that Russia has dropped its most powerful non-nuclear bomb, nicknamed the Father of All Bombs, on ISIS terrorists in Syria. If confirmed, this would be the first time Russia has employed this weapon, which is has otherwise revealed very little about, in combat. On Sept. 7, 2017, posts appeared on Twitter alleging that witnesses and activists near the Syrian city of Deir ez-Zor, had seen the weapon in action.. As yet, though, there has been no reporting in English language Russian news outlets or an official statement from the Russian Ministry of Defense.

There are few concrete details about the FOAB, formally known as the Aviation Thermobaric Bomb of Increased Power (ATBIP), and almost no official pictures or video of the bomb – one Tweet even used a picture of a mockup of the Soviet hydrogen bomb Tsar Bomba instead. It apparently uses a high explosive filler boosted with a mixture of aluminium powder and ethylene oxide, components common to other known thermobaric weapons, to create the high-intensity blast and associated shockwave.

The Russians say the complete weapon weighs just over 14,000 pounds and can create a blast equivalent to 44 tons of TNT. This would make it lighter, but more devastating that than U.S. Air Force’s 22,000 pound GBU-43/B Mother of All Bombs (MOAB), which the Russians were clearly referencing with their own nickname.