Seven al-Shabab militants were reportedly killed during an overnight airstrike in southern Somalia.

Somali intelligence officials confirmed the attack and noted that an al-Shabab commander was killed when a missile struck his vehicle. A Kenyan named Akram is also believed to have been killed.

So far, it is unknown who was behind the strike. The most likely candidate is Kenya, which launched a military offensive against the Somali rebels in October and have carried out a number of air attacks in the Lower Shabelle region.

U.S. forces have also conducted military operations in Somalia, most notably against pirates in the north. The most recent American maneuver was the January SEAL rescue of two kidnapped aid workers in the central Galguduud region.

The United States has also carried out drone strikes on al-Qaeda militants in Somalia.

Al-Shabab, which is reportedly linked to al-Qaeda, is a rebel group that operates in and controls parts of southern Somalia. With help from the African Union, the Somali government successfully expelled al-Shabab from the capital of Mogadishu last year, but the insurgents still operate with relative impunity outside the city.

According to the BBC, Friday morning's strike was too large to have been conducted by the Kenyan military, but no one has claimed responsibility.

A number of air strikes have been reported in recent months but for now no one seems prepared to own up to them -- possibility because of the potential backlash should civilians be killed, BBC's Will Ross said.