A suicide car bomber killed seven people at a checkpoint at Baghdad's Green Zone early today.
At least 13 people were injured in the blast, said local doctors.
The US military confirmed that a "vehicle-borne improvised explosive device" had exploded near the checkpoint, and said there were no US casualties.
Located in central Baghdad, the Green Zone occupies an area of four square miles on the west bank of the Tigris river.
It is the second attack in two days at the district that houses Iraq 's interim government and foreign embassies
Yesterday, a suicide bomber killed 13 and injured 15 people near the Harthiyah gate on the western edge of zone.
The US Embassy and several other missions are located in the zone, which consists of former dictator Saddam Hussein's palace and other administrative buildings.