Sheikh Mukhtar Robow, a spokesman for the Islamic movement which is leading an insurgency against the Somali government, confirmed the attack.
"I can confirm to you that the Americans bombed the town and hit civilians targets thinking that they were Islamist hideouts. They used an AC 130 plane," Robow said.
If confirmed, this would be at least the third time the US military will have conducted operations inside Somalia since 2007.
In June 2007 a US Navy destroyer shelled suspected al-Qaeda targets in mountainous and remote areas in northeastern Somalia where anti-government fighters were believed to have bases.
Earlier the same year a US aerial gunship bombed positions held by anti-government fighters in southern Somalia, coming to the aid of the Somali government forces which had ousted the Islamic Courts Union from most of the country's southern and central regions.