A US military statement said the attack happened this morning. There was no immediate comment on the airstrike from Somalia's homegrown extremist group, al-Shabab, which is allied to al-Qaida.
Somali president Mohamed Abdullahi Mohamed confirmed the airstrike, saying that Somali and partner forces destroyed an al-Shabaab training camp near Sakow, in the Middle Juba region.
He said such attacks would disrupt the group's ability to conduct new attacks within Somalia.