US hits Iran near Strait of Hormuz with 5,000-pound 'bunker buster' bomb — what makes this high-cost weapon stand out

The United States carried out a high-profile strike on Iranian missile sites near the strategic Strait of Hormuz on Tuesday, deploying some of the most powerful conventional bombs in its arsenal. The attack targeted underground facilities housing Iranian anti-ship cruise missiles, which US Central Command said posed a significant threat to international shipping in the vital waterway.

"US forces successfully employed multiple 5,000-pound deep penetrator munitions on hardened Iranian missile sites along Iran’s coastline near the Strait of Hormuz," CENTCOM said in a statement on X. The strike came as Iran had effectively blocked the strait, through which nearly a fifth of the world’s oil passes, using mines, drones, and ships.



The 5,000-pound bombs used in the strike were the GBU-72 Advanced 5K Penetrator, a weapon first deployed in 2021 and designed specifically to penetrate hardened, deeply buried targets. While each bomb reportedly cost around $288,000, they are still less powerful than the 30,000-pound GBU-57 Massive Ordnance Penetrator used in prior US strikes on Iranian nuclear sites.

What is the GBU-72 Advanced 5K Penetrator

The is a modern evolution of earlier bunker-busting bombs like the GBU-28. Developed using advanced modelling and simulation, the weapon’s design allows it to penetrate reinforced concrete or deep underground bunkers before detonating, maximising destruction to strategic targets while reducing collateral damage above ground.

The bomb has been tested extensively. In October 2021, an F-15E Strike Eagle released a GBU-72 at 35,000 feet over Eglin Air Force Base in Florida. The test series, planned by the 780th Test Squadron and flown by the 40th Flight Test Squadron, included the first-ever flight, load, and release of the 5,000-pound weapon. These trials also validated a modified tail kit originally designed for a 2,000-pound bomb, ensuring the GBU-72 could be safely deployed from fighter and bomber aircraft.

Ground tests at Eglin Air Force Base involved the largest open-air detonation ever conducted at the range, with the warhead surrounded by blast sensors and fragment-counting equipment to assess lethality. "Test series of this magnitude are never successful because of a single person or organisation," said Ronald Forch, a 780th TS programming engineer. "They are ultimately successful because every part performs in concert, like a symphony."

Middle East crisis escalates

The US strike came amid rising tensions across the Middle East. Iranian forces have threatened retaliation following the killing of security chief Ali Larijani in a separate Israeli air strike. Iranian army chief Amir Hatami warned of a "decisive and regrettable" response, while the Revolutionary Guards launched missiles at central Israel in retaliation.

Meanwhile, Gulf nations intercepted multiple drone and missile attacks. Saudi Arabia reported intercepting a ballistic missile and eight drones, Kuwait defended against a rocket and drone attack, and Qatar reported an intercepted missile near Doha. Australia also confirmed an Iranian projectile landed near its regional military headquarters in the UAE.