The guard, who was being sought, was a member of the Afghan Local Police, trained by U.S. special forces, The New York Times reported.
Brig. Gen. Ali Shah Ahmadzai said the guard allegedly coordinated the attack Wednesday in Oruzgan, in southern Afghanistan.
The newspaper said the Afghan Local Police program, which operates separately from Afghan National Police forces, is controversial because it takes groups of armed men, some of them former Taliban sympathizers, and incorporates them into government service protecting their own communities.
Critics say the program can empower abusive local militias.
Khaama Press said at least 11 people, including at least seven Afghan police service members, died Monday in a suicide bomb explosion at Jalalabad city.