Abu Omar al-Kurdi was an ethnic Kurd from the Jaff tribe.
[1] He was a veteran of Jihad in Afghanistan, where he allegedly mastered his bomb-making skills.
He returned to Iraq in 2003 where he met Zarqawi and would later become his top bomb-maker.
Allegedly, al-Kurdi's bomb-making was made possible by using hundreds of rockets and explosives stolen from Iraqi military warehouses by another member, Ammar az-Zubaidi, early in the 2003 invasion of Iraq.
By the time he was arrested on 15 January 2005, he was already responsible for 75 percent of the car bomb attacks in Iraq since August 2003 but only confessed to 32 of them.