A bomber blew up his car as he waited to be searched at a military checkpoint used by contractors and Iraqis into the government and diplomatic compound known as the Green Zone on Monday.
At least 15 people were wounded in the attack at around 0900 local time (0600GMT), the morning rush-hour.

We have to reinstate some of the clean-record army and police officers
Ghazi YawerIraqi interim president
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US 'errors' attacked
"We had stopped in the car when all we felt was a car explode next to us," one injured Iraqi civilian was quoted by Reuters news agency as saying.
Hospital sources said all the dead were Iraqi civilians.
"There were no multinational forces personnel wounded or killed. There were Iraqi casualties," said US army Lieutenant Colonel James Hutton.
The sprawling complex, which was formerly Saddam Hussein's presidential palace, is frequently attacked by insurgents.
Seven people were killed in a similar attack at a police station on the edge of the Green Zone just over a week ago.
The BBC's Peter Greste says Iraqis will see the latest attack as a potent reminder that the insurgency is still very much alive and active.
It comes a year after a bedraggled Saddam Hussein was pulled from a hole in the ground near his home town of Tikrit by US forces.
At the time, Washington had predicted the insurgency would crumble without its leader, our correspondent adds.
Security vacuum
Earlier on Monday, the US announced at least eight marines were killed in three separate incidents in Anbar, a province that includes the city of Falluja where US forces launched a major offensive last month.
There have been American air strikes and renewed clashes between US troops and insurgents in Falluja over the past 48 hours.
The US military said the marines died during "security and stabilisation operations" but it was not immediately clear if the soldiers' deaths were connected to the fighting in Falluja.
In other developments:
Seven of Saddam Hussein's former top officials are refusing meals while in detention at a secret location, US military confirms
Twenty-one people are killed when a minibus carrying extra petrol cans explodes after colliding with a car in eastern Iraq
Interim Iraqi President Ghazi Yawer blamed some of the present difficulties on the American decision to break up Saddam Hussein's entire security apparatus as soon as they had toppled the dictator last year.
He said many soldiers with a clean record were forced out, and it had left a vacuum which is proving hard to fill as new forces are slowly assembled.
But he did acknowledge that Iraqis on their own could never have toppled Saddam.
And he said the government's priority was to ensure the situation was secure enough for people to feel safe enough to go out and vote on 30 January.