The US military carried out a missile strike in Somalia targeting a suspected militant leader with ties to al Qaeda and al Shabaab, a US military official said.
The strike took place in southern Somalia, the official said, without offering further information, including the identity of the suspect or whether the strike was believed to have been successful.
Another US official, also speaking on condition of anonymity, said the operation took place in a remote area near Barawe, Somalia.
Barawe, a militant stronghold on Somalia's southern coast, was the site of a failed raid by American commandos in October targeting a militant known as Ikrima.
The US forces pulled out after a gun battle without capturing Ikrima, described as a planner and operator who has relentlessly plotted attacks on neighbouring Kenya.
Al Shabaab has been weakened by African Union troops over the past two years, ushering in some stability in many parts of the Horn of Africa country after a campaign of cross-border raids and kidnappings of Westerners and security forces.
But the rebels, who have waged a seven-year insurgency seeking to impose a strict interpretation of sharia law in Somalia, stunned the world in September when they attacked an upscale shopping mall in Nairobi, killing at least 67 people.
Late last year, the US military deepened its involvement in Somalia, establishing a unit of fewer than five troops in the capital, Mogadishu, to help advice and support African Union and Somali forces.