The Al-Qaeda-linked Al-Shabaab has been waging a bloody insurgency against Somalia's fragile federal government for more than 17 years.

The raid took place on December 31 in Beer Xaani, roughly 35 kilometres (21 miles)from the port city of Kismayo town, the United States Africa Command (US AFRICOM) said in a statement.

It was conducted "at the request" of the Somali government, AFRICOM said.

"The initial post-strike assessment indicated the air strike killed 10 Al-Shabaab militants while no civilians were harmed," it said.

The strike on Al-Shabaab follows an attack by the Islamic State group to the country's north, which was repelled by government forces.

AFRICOM will "continue to assess the results of this air strike and will provide additional information as appropriate".

Al-Shabaab carried out numerous attacks in the capital Mogadishu and other parts of the country last year, while the government pressed on with an offensive aimed at eradicating the jihadists.

Washington has invested massively for several decades in the fight against the armed rebellion.

During his first term, US President-elect Donald Trump announced the withdrawal of US troops from Somalia, a decision reversed by his successor Joe Biden.

Somalia is one of the poorest nations on the planet, enduring decades of civil war and frequent climate disasters in addition to jihadist violence.