The Islamic State of Iraq, a group of Sunni militants that includes members of Al-Qaeda, said in an Internet statement that it was behind the April 23 attack in Diyala Governorate.
The U.S. military says the attackers used one suicide truck bomber to breach the outer barrier of a security perimeter.
It says that allowed a second suicide truck bomber to drive through the barrier and explode his vehicle near a U.S. patrol base building.
(Reuters, AP)