The US defense department has confirmed that it has killed an al-Shabab leader, Adan Garar.
The Pentagon said the militant was hit by a drone equipped with Hellfire missiles in southern Somalia last Friday.
Garar was a suspect in the 2013 Westgate Mall attack in Nairobi that left 67 people dead.
The US believes Garar was overseeing operations that "target US persons and other Western interests".
He was a member of the security and intelligence wing and a "key operative responsible for coordinating al-Shabab's external operations", according to the Pentagon.
The operation took place about 150 miles (240 km) west of Mogadishu near the town of Dinsoor. Washington has supported an African Union (AU) force, which has driven the fundamentalist group from strongholds across Somalia since 2011.
The US defense department said in a statement that Garar's death "has dealt another significant blow to the al-Shabab terrorist organisation in Somalia".