At least 23 people were killed -- most of them Iraqi civilians -- and more than 60 were wounded early Sunday when a suicide truck bomber detonated a half-ton of explosives near the US-led coalition's headquarters, according to US military sources.

"We have indications that some of those that were killed were American citizens -- US contractors," said Brig. Gen. Mark Kimmitt during a Baghdad news conference. "We believe the current number at two. We're waiting for firmer confirmation."

Earlier, US military sources said that two Department of Defense workers were among the dead, but could not specify their occupations or nationalities.

Also appearing at the news conference, Iraqi Governing Council spokesman Hamid al-Kafai said at least 20 people had been killed in the attack, The Associated Press reported.

Coalition officials earlier said three others had died at al-Karama hospital. 

L. Paul Bremer, the top US civilian administrator in Baghdad, condemned the bombing, which he said "was clearly timed to claim the maximum possible number of innocent victims."

Bremer said the plan to hand over authority to a new Iraqi government in July "remains unchanged."

Shortly before 8 am (local time) Sunday, a white Toyota pickup truck carrying almost 1,000 pounds (500 kilograms) of military-grade, plastic explosives tried to enter "Assassin's Gate" -- the northern entrance to the heavily fortified Green Zone, which houses coalition headquarters, Brig. Gen. Mark Hertling of the 1st Armored Division said.

Instead, the driver -- who was also killed in the blast -- detonated the explosives about 50 feet (16 meters) from the entrance, according to military officials.

About 90 percent of the explosion was absorbed by blast barriers, protecting the headquarters from damage, according to Capt. Jason Beck of the 1st Armored Division.

At the US military's 28th combat support hospital in the Green Zone, 20 people were dead and 29 wounded, including three US soldiers and three US civilians, Beck said.

In addition to the three deaths reported at al-Karama hospital, other hospitals reported receiving a total of 34 wounded Iraqis, bringing the total of wounded Iraqis to 63.

Most of the dead are believed to be Iraqi civilians, although sources said two Iraqi police officers are among the dead.

The bomb took place as many Iraqis lined up at security checkpoints near the gate to start their workday or apply for a job at the Coalition Provisional Authority headquarters.

Traffic packed a major intersection just outside the entrance at the time of the blast and many of the Iraqis killed were in their vehicles waiting to pass through a checkpoint, a US military spokesman said.

"We're hearing that the fireball was huge and that they didn't have a chance," the unnamed spokesman said, referring to the Iraqis inside the cars. The force of the blast destroyed at least six vehicles, Beck said.

One Iraqi citizen was able to pull two people from a burning car, but could not save the other two because of the intense heat.

An Iraqi driver who survived the blast said the force sent his car into the air, landing 109 yards (100 meters) away.

"I was driving ... toward the bridge when a car exploded," said Jasim Mohammed, who had a visible injury to his face. "I felt my car going up in the air and landing again. All of a sudden, everything turned red and there was a very strong explosion."

Initial video of the aftermath showed three vehicles engulfed in flames, and several Iraqi civilians lying on the ground, bloodied. US troops and tanks were on the scene and gunshots could be heard in the background.

Col. Ralph Baker, the 2nd Brigade Commander of the 1st AD, said there was no exchange of gunfire as a result of the incident.

"Immediately after the bomb exploded, soldiers assumed a defensive posture and immediately assisted Iraqi citizens by rendering first aid to them," Baker said.

The blast happened a day after a powerful roadside bomb ripped through a Bradley Fighting Vehicle north of Baghdad, killing three US soldiers and two Iraqi civil defense forces.

Also Sunday, a roadside bomb detonated in Basra near a British military vehicle, but no one was injured, according to a British military spokesman.

Late Saturday, two Iraqis were killed in Tikrit when an explosive device detonated inside the car they were riding in, military sources said. A third occupant of the white Mercedes has been hospitalized and will be questioned, the sources said. There were no US casualties in the blast.

(China Daily January 19, 2004)