A security officer said cars carrying bombs were in line to enter the Green Zone when they exploded, killing nine people, including Iraqi soldiers, BBC reported.
The string of explosions began when an improvised explosive device was tripped near Baghdad University, injuring two people, The New York Times reported. A few minutes later, suicide bombers detonated their explosives at the checkpoint to enter the Green Zone, which houses many foreign embassies and Iraqi government offices, officials said.
A government spokesman blamed al-Qaida for the attacks.
"The significance of targeting is just for the media in order to prove their presence," he said.
The attacks come as preparations are being made for an Arab summit next month in the Green Zone, but officials said the recent unrest may force its postponement, the BBC reported.