U.S. forces fired on al-Shabab militants while assisting in an attack by Somali government and African Union troops on a militant base.
The incident occurred Thursday in the village of Sabiid, about 40 kilometers west of Somalia's capital, Mogadishu.
A U.S. defense official tells VOA U.S. forces conducted "defensive fire" against al-Shabab fighters, after Ugandan African Union troops came under attack while trying to eliminate a militant checkpoint.
A senior Somali official, speaking on condition of anonymity, says U.S. helicopters fired missiles, hitting and damaging three al-Shabab armed cars. The official says at least seven militants were killed.
US support role
U.S. troops officially play an "advise and assist" role with the African Union force in Somalia, known as AMISOM.
Earlier this week, U.S. forces were involved in a raid on an al-Shabab base in the village of Toratorow, in which an unknown number of militants were captured or killed.
A Somali security official, Mohamed Nur Gabow, told VOA U.S. forces played a "lead role" in that operation. AFRICOM, the U.S. military command center for Africa, denied U.S. soldiers were in the lead.
The United States has trained a Somali government commando unit known as "Danab" or "Lightning," consisting of 500 soldiers who conduct special operations.
The Somali government has battled al-Shabab since the al-Qaida-linked militant group formed in 2006. The U.S. State Department designated al-Shabab a terrorist group in 2008 and has given the Somali government financial and military support to combat it.
VOA National Security Correspondent Jeff Seldin contributed to this report.