In a statement published on Wednesday, the Pentagon confirmed rumors that Garar was killed on March 12 when a US drone aircraft struck a vehicle in which he was travelling near Diinsoor, Somalia.

Garar was overseeing operations that "target US persons and other Western interests in order to further al Qaeda's goals and objectives" and posed a "major threat to the region and the international community," the Pentagon said.

"His death has dealt another significant blow to the al-Shabab terrorist organization in Somalia," the statement added.

Shortly after the strike last Thursday, Kenyan officials told media that Garar had been taken out, but the Pentagon was unable to publicly confirm his death until now.

Al-Shabab is an ultra-conservative Islamic militant group that has steadily lost territory to a military offensive by Somalia and African Union (AU) forces. It had controlled Mogadishu and southern Somalia until it was driven out of the capital in 2011.

The US is thought to have carried out several drone strikes against the al-Qaeda-linked group in Somalia in support of the AU forces.

ksb/bk (AFP, AP, dpa)