Abdel-Zahraa Othman, also known as Izzadine Saleem, was among at least eight killed in the blast, according to Redha Jawad Taki, of the Supreme Council of the Islamic Revolution in Iraq, a Shi’ite Muslim organisation.
The presidency of the governing council is a rotating position.
The bomb destroyed three cars waiting to enter the Green Zone, the heavily fortified area around coalition headquarters, Colonel Mike Murray said.
A rocket also struck the compound of the coalition headquarters on Saturday, wounding one US soldier and one civilian.
Nine Iraqis were killed in Nasiriya during clashes with Italian troops, hospital officials said.
In the holy city of Karbala, where US troops are pitted against fighters loyal to the radical cleric Muqtada Sadr, five Iraqis died.
