A U.S. military airstrike recently targeted the al-Qaeda-linked al-Shabaab terrorist group in southern Somalia, killing five jihadists and wounding two others, reveals the Pentagon.

Ugandan troops, backed by a very small contingent of U.S. military advisers, raided an illegal taxation checkpoint in rural southern Somalia, west of the country’s capital Mogadishu, NBC News learned from Capt. Jeff Davis, a Pentagon spokesperson.

The U.S. military’s mission was to advise and assist, noted Davis.

American troops have been supporting their Somali counterparts and their allies in their fight against al-Shabaab for a few years.

In early March, U.S. manned and unmanned aircraft bombed an al-Shabaab training camp in Somalia, killing over 150 jihadists.

Up to 20 members of al-Shabaab, also spelled al Shabab, attacked the Ugandan troops during the recent raid.

In response, the U.S. military called in a “defensive” airstrike.

Although U.S. ground forces were “nearby” at the time of raid, they did not open fire on al-Shabaab or vice versa.

NBC News quoted an unnamed defense official as saying that an MQ-9 Predator drone that was flying at the time and capable of providing a quick response carried out the strike.

An estimated 50 American service members are currently deployed to al-Shabaab’s home country in support of the African Union Mission in Somalia (AMISON).

“This is the second kinetic incident with the U.S. in Somalia this week,” reports NBC News. “The first incident occurred on Tuesday when a small group of U.S. military supported a Somali military mission against a group of al Shabab militants.”

Prompted by intelligence that the jihadist group was planning to attack a nearby AMISON compound, the U.S. military supplied helicopters as well as advise and assist for Tuesday’s mission.

Al-Shabaab has pledged allegiance to Islamic State (ISIS/ISIL) rival al-Qaeda.

However, Reuters reported in October 2013 that “a senior al Shabaab commander and about 20 of his followers have pledged allegiance to Islamic State, the first move of its kind to emerge in the Somali militant group.”

The commander was identified as Abdiqadir Mumin from the Puntland region of Somalia.

Mumin is now leading a growing pro-ISIS group in Somalia, notes Voice of America (VOA).

Nevertheless, ISIS jihadists have been engaged in turf battles with al-Shabaab in Somalia.

Land battles between the two groups and pressure from the Kenyan military, backed by Somali troops, appear to be pushing al-Shabaab into from Somalia into neighboring Kenya.

Abdi Hassan Hussein, the former Director of the U.S.-backed Puntland Intelligence Agency (PIA) has reportedly warned that the number of pro-ISIS jihadists in Somalia has grown.

The number of pro-ISIS militants in Somalia has increased from 20-30 men when it was founded in October 2015 to between 100-150 now.

“They have graduated their first units and they have received their military supplies,” said Hussein.

“They received military supplies from Yemen – weapons, uniform, ISIS sent trainers who inspected their bases, and they have started sending financial support,” he added. “The weapons’ shipment was delivered by sea from Mukallah city in Hadramouth, it has arrived from the Red Sea coast of Somalia in February and March this year.”