Soldiers assigned to the U.S. Army John F. Kennedy Special Warfare Center and School participate in reconnaissance training during the Tactical Skills portion of the Special Forces Qualification Course (SFQC) at Camp Mackall, North Carolina, Jan. 9, 2023. (U.S. Army photo illustration by K. Kassens)

U.S. forces extensively rehearsed a secret raid to take out a senior Islamic State financial operative this week, using a specially-built recreation of the rugged target area, U.S. officials said.

The Pentagon revealed on Thursday that U.S. forces conducted an assault in northern Somalia the day before and killed Bilal-al-Sudani, an ISIS leader in the country who has played a key role funding operations around the world — including in Afghanistan where 13 US service members were killed in a 2021 ISIS bombing — and growing the group's presence in Africa.

Defense Secretary Lloyd Austin said in a statement that the raid "resulted in the death of a number of ISIS members." A senior Biden administration official told reporters that 10 other fighters were killed by U.S. forces. No civilians or U.S. troops were injured during the operation, they said.

To carry out the operation, the official said special forces rehearsed the operation at sites that were specifically built to recreate, or simulate, the terrain — a remote, mountainous cave complex — where the operation would eventually take place.

This preparation and training strategy is similar to one used by Navy SEAL forces ahead of the dramatic 2011 Neptune Spear raid that killed Osama bin Laden.

Admiral William McRaven, who planned and executed that raid in Pakistan, wrote in his 2019 book "Sea Stories" that the CIA built a mock-up of the compound in Abbottabad, where bin Laden lived. U.S. forces used the mock-up to practice what their ground movements and helicopter approaches would look like during the actual raid.

McRaven wrote that the CIA "had done a masterful job of constructing the mock-up." A chain-link fence simulated the walls of the compound, while a "Lego formation" of shipping containers simulated the living spaces.

Still, McRaven said, there were a few unfortunate shortcomings due to a lack of time and intelligence. For example, the CIA was unable to replicate the thickness of the walls surrounding the compound, nor could it assess what the inside of the living quarters looked like, gaps that would prove problematic during the actual raid.

That a similar approach was used for Bilal-al-Sudani speaks to his importance as a target.

Wednesday's raid in Somalia comes as the United States and partner forces continue to track down ISIS fighters in Syria. U.S. Central Command said in late November that a raid carried out by local Syrian forces weeks prior led to the death of Abu al-Hassan al-Hashimi al-Qurayshi, who was then the leader of the terror group.

Meanwhile, the raid in Somalia also took place during a week in which U.S. forces carried out several strikes against al-Shabaab, a Somalia-based terror group with links to Al Qaeda that Bilal-al-Sudani previously supported. US Africa Command said 32 al-Shabaab fighters were killed in two separate engagements on January 20 and 23.

"This action leaves the United States and its partners safer and more secure, and it reflects our steadfast commitment to protecting Americans from the threat of terrorism at home and abroad," Austin said of the latest raid. "We are grateful to our extraordinary service members as well as our intelligence community and other interagency partners for their support to this successful counterterrorism operation."