A SUICIDE bomber blew up his car outside the main US headquarters in Baghdad yesterday, killing 16 Iraqi civilians and two US Defense Department staff in the deadliest attack in Baghdad since the capture of Saddam Hussein.

The bomb exploded right outside one of the main gates of the ?Green Zone?, formerly one of Saddam?s palace complexes and now the headquarters of the US-led administration.

A spokesman for the US 1st Armored Division said the car exploded after joining a queue of vehicles waiting to enter the base, which is heavily guarded by US troops. Cars blazed in the street after the blast and wounded people lay on the ground in pools of blood. A stream of ambulances ferried away the wounded through thick early-morning mist.

A US Army spokeswoman said she could not confirm the nationality of the Defense Department employees killed in the blast. Many foreign contractors in Iraq are employed by the Department.

A US soldier said almost all the victims appeared to be Iraqi civilians, mostly people who work in the base and were waiting at the gate to be searched before entering. One US soldier was believed injured, he said.

Sunday is a working day in Iraq and the bomb went off just after 8 a.m. (0500 GMT), when many people would have been on their way to the office.

One man could be seen lying on the ground, only a slight twitch showing he was alive. Another was slumped on the kerb. At Yarmouk Hospital, more than a dozen people were admitted. Insurgents resisting the US occupation regularly attack the US military and those they see as cooperating with the occupiers.

The last major attack in the capital was a car bomb outside a major city restaurant on New Year?s Eve, killing eight people and wounding 30.

Fiona O?Brien & Andrew Marshall