The US service member killed in action was a Navy SEAL, a US defense official told CNN.
A US military official confirmed that this is the first US service member killed in action in Somalia since 1993, when two Black Hawk helicopters were shot down and 18 American soldiers were killed in the Battle for Mogadishu.
The incident occurred Thursday during an operation against local al Qaeda affiliate al Shabaab 40 miles west of Mogadishu in the Shebelle region. The wounded, including an interpreter who was also a US citizen, are receiving medical attention, another US defense official told CNN. The troops came under small arms fire.
The US troops were part of an ongoing US military program to advise and assist Somali ground forces. The mission was not part of the stepped-up effort in Somalia to conduct airstrikes and ground missions against terror targets.
"This was an operation targeting an al Shabaab group that had been associated with attacks on US, Somali and AMISOM forces," US Navy Capt. Jeff Davis, a Pentagon spokesman, told reporters Friday, referring to the African Union mission there.
The US Navy SEALs and their Somali National Army partners were flown in via helicopter and came under fire "in the early phase of the mission" after landing near their target, an al Shabaab compound, according to Davis, adding that "the attackers were quickly neutralized on the ground."
"This was done under the same authorities that we've had since we began our operations there in 2013, which is to advise and assist on these types of missions," Davis said.
"US forces are assisting partner forces to counter al Shabaab in Somalia to degrade the al Qaeda affiliate's ability to recruit, train and plot external terror attacks throughout the region and in America," according to a news release from US Africa Command.
US Africa Command announced last month that it was sending sending "dozens" of additional troops to Somalia to train and equip the Somali National Army and the forces participating in the African Union Mission there.
A US military official has told CNN that the new contingent would consist of about 40 soldiers.
The US troops will join the small number of US Special Operations Forces already there providing counterterrorism support to local forces battling al Shabaab. That advisory mission, consisting of about 50 Special Operations Forces, has been underway since 2013.
The new training effort comes as US military leaders see opportunities to work with Somalia's newly elected president, Mohamed Abdullahi Farmajo, a dual US-Somali citizen who has embarked on a series of aggressive military reforms amid an ongoing al Shabaab bombing campaign that has repeatedly struck Mogadishu.
CORRECTION: This story has been corrected to reflect that the incident took place on Thursday.