TEHRAN — The United States used its most powerful non-nuclear bomb — the GBU-57A/B Massive Ordnance Penetrator, or "bunker buster" — in its strikes on Iran’s nuclear sites, marking the weapon’s first known use in combat.

The 30,000-pound bomb, packed with 6,000 pounds of explosives, was dropped on fortified Iranian nuclear facilities including the underground Fordo enrichment site, according to U.S. defense sources and military analysts.

The GBU-57, designed specifically to target deeply buried weapons of mass destruction, was deployed by American B-2 Spirit stealth bombers.

These long-range heavy bombers are the only aircraft capable of carrying the GBU-57 and flew from the United States across the Pacific on Saturday as regional tensions soared following Israel’s war with Iran.

Known for their radar-evading capabilities, B-2 bombers can travel up to 11,500 miles with aerial refueling, allowing them to reach any global target in hours.

Their deployment underscores the seriousness of the U.S. strike, which targeted some of the most secure sites in Iran’s nuclear program.

The Fordo facility, buried deep in a mountain near Qom, is considered Iran’s most heavily protected site. The GBU-57 is uniquely designed for such targets — capable of penetrating 200 feet (61 meters) underground before detonating.

Multiple bombs can be used in sequence to compound the destructive force by creating deeper craters.

Developed in the early 2000s by Boeing and tested at the White Sands Missile Range in New Mexico, the MOP had never been used in live combat until now.

It surpasses even the “Mother of All Bombs” (MOAB) in destructive capability and was explicitly built for missions where conventional weapons cannot reach hardened underground sites.

In 2015, the U.S. Air Force said the MOP was engineered to “find and destroy weapons of mass destruction in well-protected facilities.” — Agencies