The ‘father of all bombs,’ (FOAB) as it is known, was created in 2007. Although it has never been used, the few details released by Russian authorities since suggests the thermobaric weapon is much more powerful than the US’ ‘mother of all bombs’ (Moab), which killed up to 96 Isis militants in Nangarhar province in an 17 April strike.
Russian media says that when detonated the Foab has an explosion power equivalent to 44 tons of TNT, compared to 11 tons for the US’s GBU-43/B, and has double the blast radius - just under 1,000 feet.
Thermobaric bombs explode at much higher temperatures than conventional munitions, meaning they inflict damage via supersonic shockwaves, effectively vaporising living things within the blast radius. The sustained blast and pressure waves are similar to those of a small nuclear detonation.
"We believe it's real," retired US Colonel Rick Francona, an analyst and former military attache in Syria, told CNN. "The Russians have been among the pioneers of these thermobaric bombs."
The US first tested the Moab in 2003, after which Moscow began to develop its own similar weapon.
It is not known how many are in Russia’s arsenal, although the number is not thought to be high as the technology is both expensive and too sensitive to export. It has never been used in combat.
The Moab’s only deployment to date was last week’s strike on a network of fortified tunnels used by Isis to attack Afghan government forces in the east of the country.
Long thought of as an expensive white elephant, each of the 20 bombs in the US’ arsenal cost around $16million (£13million) to manufacture.
US forces have been conducting cleaning operations in the area since the strike, but have not released any official damage assessments.
The Afghan authorities have claimed that the US has not allowed them access to the blast site, and any civilian casualties are currently not known.