Another U.S. 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 U.S. forces pulled out after a gun battle without capturing Ikrima, described as a planner and operator who has relentlessly plotted attacks on neighboring 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.