A U.S. Navy SEAL has become the first American military casualty in Somalia in decades, killed while accompanying Somali forces raiding an al-Qaeda-linked al-Shabaab hideout.

“U.S forces were conducting a partnered operation—targeting an al- Shabaab group that had been associated with attacks against US, Somalia and AMISOM forces,” from the African Union Mission in Somalia, Pentagon spokesman Capt. Jeff Davis told reporters Friday.

The joint patrol was attacked on the ground while approaching the enemy compound, after being dropped off by U.S. helicopters.

“This was a Somali mission,” Davis said. “We helped bring them in with our aircraft. That’s when our forces came under fire.”

Davis would not say if the mission was successful, but said there was no need for air strikes after the joint patrol moved through the compound.

“The attackers were quickly neutralized on the ground,” he said.

A senior defense official confirmed to The Daily Beast that the casualty was a SEAL, as first reported by CNN. Navy SEAL spokesmen did not immediately respond to requests for comment, as per Pentagon regulations requiring a 24-hour wait before identifying a combat casualty’s name or unit. A handful of U.S. service members were injured, but Davis declined to say how many.

The roughly 50 U.S. special operators stationed in Somalia are part of a mission launched under the Obama administration in 2013 to help Somalia rid itself of an al-Qaeda linked group that has carried out bloody attacks inside the country and nearby. The Trump administration expanded their authority to operate unilaterally in Somalia in March, but Davis said the raid was conducted under the Obama-era guidance allowing advise and assist missions.

The U.S. National Counterterrorism Center says al-Shabaab is responsible for frequent terrorist attacks within Somalia, and has claimed responsibility for high-profile violence like the September 2013 Westgate mall attack in Nairobi that killed 67 people, and the April 2015 massacre of some 150 mostly Christian university students in Garissa, Kenya

Davis said this is the first U.S. combat death in Somalia since the 1990s. Eighteen U.S. troops were killed there and around 80 injured in 1993 when Somali militia brought down two U.S. Black Hawk helicopters in Mogadishu during a special operations raid.

This is the third U.S. service member killed in action in a little more than a week. On April 27, two soldiers died during a raid in Afghanistan’s Nangarhar Province.