WASHINGTON — A member of the Navy SEALs was killed on Thursday during a raid in Somalia against the Islamic militant group known as the Shabab, Pentagon officials said.

Defense Department officials said the service member was in the country as part of an advise-and-assist mission alongside members of the Somali National Army. He was killed in an operation near Barii, about 40 miles west of Mogadishu, the capital, according to a statement from the United States Africa Command.

Separately, a Defense Department official, speaking on the condition of anonymity to discuss delicate matters regarding Special Operations forces, said that the service member killed was part of the Navy SEALs.

“We continue to support our Somali and regional partners to systematically dismantle this Al Qaeda affiliate, and help them to achieve stability and security throughout the region as part of the global counterterrorism effort,” Africa Command said in the statement.

The death of the SEAL member comes as the American military’s campaign against the Shabab in Somalia has been expanding over the past several years. The Islamist group is complex, with some factions focused on controlling Somalia, while others want to participate in external terrorist operations in line with Al Qaeda’s global war.

 

In 2013, the group carried out the attack at the Westgate mall, in Nairobi, Kenya, that killed more than 60 people and wounded more than 175. Since then, it has adopted more sophisticated forms of terrorism, including nearly bringing down a Somali airliner in February 2016 with a bomb hidden in a laptop computer.

To counter the Shabab, the United States has increasingly used Special Operations forces, airstrikes, private contractors and African allies. Hundreds of American troops now rotate through makeshift bases in Somalia, the largest military presence since the United States pulled out of the country after the “Black Hawk Down” battle in 1993. They have served as trainers and advisers to African Union and Somali government forces, and they have sometimes participated directly in combat. Military officials said they believed this was the first American combat death in Somalia since the 1993 battle.

 

About 200 to 300 American Special Operations forces have been working with soldiers from Somalia and other African nations like Kenya and Uganda to carry out more than a half-dozen raids every month, according to senior American military officials. The Navy’s classified SEAL Team 6 has been heavily involved in many of these operations.

The Pentagon has acknowledged only a fraction of these missions. But even the publicly available information shows a marked increase in recent years. The Pentagon announced 13 ground raids and airstrikes in 2016, up from five in 2015, according to data compiled by New America, a Washington think tank. Those strikes killed about 25 civilians and 200 people suspected of being militants, the group found.