They are secret. They are kinetic. They are made of rubberised rocket fuel. And they fire up destroying absolutely everything they come across, bouncing through bunkers, filling buildings with extremely hot flames, obliterating everyone and anything inside with fierce heat. The Pentagon officially calls them "kinetic fireball incendiaries". Other people call them kinetic rocket fire balls, and the way they work make them absolutely terrifying weapons.
The difference between these fireballs and other high-temperature incendiary weapons like the CrashPAD or the Shredder—two modified bombs designed to eliminate Weapons of Mass Destruction—is that these don't do a good job on keeping hazardous substances under control. Once the bomb—made of explosive and incendiary material—hits the target, there's always an ejection of material to the atmosphere, which could be dangerous for the population or the troops.
The kinetic rocket fire balls, however, don't explode. Once they hit their target—delivered by a modified bomb—and ignite, they just bounce randomly finding their way across every part of the structure. In the process, they emit an extremely high temperature flame, vapourising everything around them at 1,000ºF (538ºC). This behaviour, bouncing everywhere and reaching every place, makes them extremely effective at destroying any kind of substance or contents in the structure.
In fact, these Weapons of Bouncy Destruction can be used against both chemical or bacteriological facilities, as well as nuclear facilities, without breaking the buildings and spreading radioactivity. For now, they are "secret" and have never been used in real action—or so they said—but they have been tested successfully in underground bunkers and may be already under limited production.
And yes, you can cue in the Jerry Lee Lewis. Now. [Danger Room]