It said US forces conducted the strike on Thursday in conjunction with Somalia's government about 30 miles (48 kilometers) southwest of Mogadishu.

The Shabaab was pushed out of Somalia's capital in 2011, and subsequently from other towns and cities, by soldiers from the African Union Mission in Somalia (AMISOM).

But the Islamists still hold sway in large parts of the countryside. They launch regular gun and bomb attacks on government, military and civilian targets in Mogadishu as well as ambushes on military convoys and outposts.

Somali commandos often carry out operations side-by-side with the American forces that train them. Air assaults and missile strikes have increased in recent months.

This was the 11th American strike against the Shabaab since the beginning of the year.