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What are bunker buster bombs? US uses MOP, its largest non-nuclear missile, to strike Iran

Donald Trump revealed operational details, saying that six MOP bombs, each weighing 30,000 pounds, were deployed on Iran's Fordow.

Updated on: Jun 22, 2025, 11:45:18 IST
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The United States used its most powerful conventional weapon—the Massive Ordnance Penetrator (MOP), or bunker buster bomb—in a high-impact military operation targeting Iran’s underground nuclear facility at Fordow on Saturday.

FILE - In this photo released by the U.S. Air Force on May 2, 2023, airmen look at a GBU-57, or the Massive Ordnance Penetrator bomb, at Whiteman Air Base in Missouri. (File Photo/AP)
FILE - In this photo released by the U.S. Air Force on May 2, 2023, airmen look at a GBU-57, or the Massive Ordnance Penetrator bomb, at Whiteman Air Base in Missouri. (File Photo/AP)

US President Donald Trump, who in a social media post suggested, “Fordow is gone,” said that the attack targeted nuclear sites in Natanz and Isfahan too.

“We have completed our very successful attack on the three Nuclear sites in Iran. A full payload of BOMBS was dropped on the primary site, Fordow." Trump said, confirming that all planes are now outside of Iran air space. Follow Israel Iran war live updates.

In an interview with Fox News, Trump further revealed operational details, saying that six MOP bunnker buster bombs—each weighing 30,000 pounds—were deployed on Fordow. Meanwhile, 30 Tomahawk Land Attack Missiles (TLAMs) were fired by US Navy submarines to target Natanz and Esfahan, which he claimed “destroyed all three nuclear facilities completely.”

Also Read | ‘Either peace or tragedy’: What Donald Trump said in speech after US strikes on Iran | Top quotes

The Fordow facility, long suspected of housing uranium enrichment infrastructure deep within the mountains near Qom, is widely considered one of Iran’s most fortified nuclear sites. Analysts believed it can only be effectively penetrated by the MOP, a weapon exclusively in the US arsenal.

What is the MOP and why is it so powerful?

The GBU-57 Massive Ordnance Penetrator is the largest non-nuclear bomb in the US inventory. Built by Boeing and guided by GPS, it is engineered specifically to target deeply buried and hardened bunkers.

According to a US air force fact sheet cited by CBS News, the MOP measures 20.5 feet in length and 31.5 inches in diameter, and weighs just under 30,000 pounds—including 5,300 pounds of high-explosive material.

The bomb can burrow more than 200 feet through reinforced concrete before detonating. Its casing, made from high-performance steel alloy, helps it withstand the immense impact forces upon penetration. The Air Force notes the MOP’s explosive yield is more than 10 times greater than that of its predecessor, the BLU-109.

Because of its size and weight, only the B-2 Spirit stealth bomber is capable of carrying and deploying the MOP.

The B-2’s stealth capability allows it to evade radar and air defenses, making it the ideal platform for strikes on heavily protected sites like Fordow. Each B-2 can carry up to two MOPs in its internal weapons bay.

An unconfirmed report by The New York Times claimed that the B-2 bombers which struck Iran's nuclear sites flew non-stop for 37 hours straight from their base in Missouri, refuelling multiple times mid-air during the long-range mission.

‘Only the US could have done this’

Defense analysts have long argued that Fordow's deeply buried infrastructure—shielded by 60 to 90 meters of rock—would require a weapon like the MOP to neutralize.

“Each bunker buster can be independently targeted and released, making it possible to deliver a MOP right on top of another MOP,” Bloomberg quoted Rebecca Grant of the Lexington Institute. She added that US drone surveillance likely played a role in refining the final strike coordinates.

Grant also emphasised that Fordow and other Iranian nuclear installations have been under US observation for years, helping planners build a precise targeting profile.

The MOP was developed by Boeing under a Pentagon contract, with at least 20 units built by 2015.

  • Priyanshu Priya
    ABOUT THE AUTHOR
    Priyanshu Priya

    Priyanshu Priya is a journalist with nearly three years of newsroom experience, driven by a deep belief that stories, when told right, can shape conversations and hold power to account. Currently working as a Senior Content Producer with Hindustan Times, she writes on a wide spectrum of issues, from Indian politics and Delhi’s public concerns to global trade tensions and high-stakes crime stories. Priya joined HT at a pivotal moment, as Operation Sindoor was unfolding, and has since covered some of the most defining developments in recent times. Her reporting spans the Air India plane crash and the Pahalgam terror attack to India–US trade tensions, unrest in the Middle East, and key Assembly elections across states. She thrives in the fast-paced world of breaking news. In 2025–26, she was recognised with the Hindustan Times Digi Journo of the Q3 Award for driving over 4 million page views in a single month. A postgraduate in English Journalism from the Indian Institute of Mass Communication (IIMC) and a Mass Communication graduate from Patna Women’s College, Priya began her news career with the Zee News English team, where she extensively covered the Lok Sabha Election 2024, along with the Delhi and Maharashtra Assembly elections. When she’s not tracking or writing the next big development, she unwinds by watching series and films, reading books with strong female protagonists, and revisiting comfort shows for the familiar ease they bring when life feels a little too jittery.Read More

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