( CNN ) The United States conducted an airstrike Monday in Somalia against Al-Shabaab , said Navy Rear Adm. John Kirby , Pentagon press secretary . The strike , which took place in the area of Saakow , was targeting a senior leader of the Islamist militant group . `` At this time , we do not assess there to be any civilian or bystander casualties . We are assessing the results of the operation and will provide additional information , when appropriate , as details become available , '' Kirby said in a statement . The strike was carried out by an unmanned aircraft , and was an operation of the U.S. Defense Department , according to a U.S. defense official , who spoke on the condition of anonymity . On Saturday , Somalia government forces captured a top Al-Shabaab commander , said two of the country 's military officials . Zakariya Ismail Ahmed Hersi , Al-Shabaab 's intelligence chief , was captured in a house near the town of El Wak , Somali military commander Isack Hussein Mursal told state-run radio . He was a close associate of former Al-Shabaab leader Ahmed Abdi Godane , who was killed in a U.S. airstrike near Barawe city in September . The capture came after militants with the group , which is linked to al Qaeda , attacked a large African Union base in Mogadishu last week , killing three Ugandan soldiers and a civilian . Al-Shabaab has said that attack was revenge for the U.S. airstrike that killed Godane . The State Department had offered a $ 7 million reward for information on Godane 's location . CNN 's Omar Nor and Susanna Capelouto contributed to this report .
An unmanned drone carried out the strike , said a Pentagon official . Another U.S. official said the results of the operation are being assessed . Al - Qaeda is an Islamist militant group , similar to Al Qaeda .