What is the R9X Hellfire, the precision ‘ninja bomb’ that killed al-Zawahiri?

Al Qaeda leader Ayman al-Zawahiri was killed Monday by America’s secretive and gruesome R9X Hellfire missile — which is also known as the “flying Ginsu.”

The strangest variant in the Hellfire family of missiles — built as a precision weapon of targeted assassination — the R9X’s most distinguishing characteristic is that it doesn’t explode and simply uses its weight, momentum and blade-like appendages to kill.

First revealed by the Wall Street Journal in 2019, the modified R9X trades the standard Hellfire’s explosive warhead for a halo of six metal fins that look like swords and are sharp enough to slice through concrete and steel on their way to a target.

The lethal payload has earned the R9X nicknames like “the flying Ginsu” or “the Ninja bomb” within the defense community.

Designed to be launched from an unmanned drone, the 100-pound R9X deploys the blades through its skin while in flight.

One US official described the weapon to the Wall Street Journal as a “speeding anvil” falling from the sky — with knives.

To its proponents in the US defense community, the weapon’s design allows it to minimize collateral casualties, smashing into and slicing through a lone target rather than exploding in an expanding ball of hot shrapnel like a conventional Hellfire.

Some have even suggested the weapon — which originated during the Cold War as an anti-tank missile designed to be fired from a helicopter — could kill the passenger of a car without harming the driver.

Those claims have not been verified, and neither has the missile itself — the US government remains tight-lipped in public about its very existence.

The weapon’s use is usually suggested by a tell-tale entry hole and a lack of explosion damage.

The R9X is believed to have been used only a half-dozen times since its development began in 2011. It was likely first fielded in 2017.

Officials have said the weapon requires very accurate intelligence precisely because it is supposedly so accurate — one would need to know not simply which car or building a target was in, but specifically where they were sitting or standing.