"We are aware of reports alleging civilian casualties resulting from this operation, and we take these reports seriously," AFRICOM said in a statement.

"Africa Command will review any information it has about the incident, including any relevant information provided by third parties."

US forces, in an advise-and-assist capacity, partnered with Somali forces in a raid targeting Islamic Al-Qaeda militants aligned with the Shabaab group on Wednesday night.

Ali Mohamed Moalin, a traditional elder close to Afgoye in Lower Shabelle where the raid took place, said "two military helicopters" were involved as well as "some foreign special forces."

"There are five dead bodies of innocent farmers who have been killed by the special forces last night," Moalin said.

"Several other people were wounded, and three others taken alive in the helicopters," he said, a claim that could not be immediately verified.

If AFRICOM determines information supporting the allegations are deemed credible, it "will determine the next appropriate step."