One U.S. special operations member was killed and four others were wounded in an attack by al-Shabab militants Friday in southern Somalia.

A partner force service member also was wounded in the attack in Jubaland, Somalia, U.S. Africa Command announced Friday.

One of the four wounded U.S. troops received sufficient medical care in the field, while the three others and the wounded partner force member were medically evacuated, AFRICOM said.

The combined force of Somali, Kenyan and American troops came under mortar and small-arms fire about 2:45 p.m. local time.

About 800 Somali and Kenyan forces were conducting a multi-day operation about 220 miles southwest of Mogadishu when the attack occurred, AFRICOM said.

Their goal was to “clear al-Shabab from contested areas, liberate villages from al-Shabab control, and establish a permanent combat outpost designed to increase the span of Federal Government of Somalia security and governance,” AFRICOM said in its statement.

The U.S. troops were providing advice, assistance and aerial surveillance during the mission.

The American troops were supported by an armed drone, according to the New York Times.

SITE Intelligence Group, a think tank that monitors militant and terror organizations, said al-Shabab had claimed responsibility for a “fierce attack” on a joint U.S.-Somali outpost near Kismayo.

The establishment of the outpost and presence of U.S. forces sheds some light on an otherwise shadowy mission by U.S. special operations forces in the region.

Last October, four U.S. soldiers were killed in an ambush in Niger. That attack threw the spotlight on U.S. military activities in Africa, which had largely been kept under wraps.

U.S. Africa Command officials have routinely told Military Times that the U.S. footprint in Somalia hovers around 500 troops, but that hasn’t slowed U.S. efforts in targeting al-Shabab militants.

In this Feb. 17, 2011, file photo, hundreds of newly trained al-Shabab fighters perform military exercises in the Lafofe area some 18 km south of Mogadishu, in Somalia. (Farah Abdi Warsameh/AP)
In this Feb. 17, 2011, file photo, hundreds of newly trained al-Shabab fighters perform military exercises in the Lafofe area some 18 km south of Mogadishu, in Somalia. (Farah Abdi Warsameh/AP)

On June 2, a U.S. airstrike outside the northern coastal city of Bosasso on the Somali terror group killed 27 fighters.

And last Thursday, a strike outside Mogadishu killed 12 fighters.

Military officials with AFRICOM have estimated al-Shabab’s size to be roughly 3,000 to 6,000 fighters.

The resurgent militant group dominates rural areas in the southern part of the country and controls roughly 20 percent of Somalia.

ISIS also has a small presence in the region, but their numbers pale in comparison to al-Shabab, estimated at just several hundred fighters.

U.S. forces carried out their first strike against ISIS in the region in November.

Somalia has been an important counter-terrorism focus by U.S. forces. Al-Shabab militants have allegiances and connections to al-Qaeda.

This story is breaking and will be updated when more information is available.