"We have indications that some of those that were killed were American citizens -- U.S. 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, U.S. military sources said that two Department of Defense workers were among the dead, but could not specify their occupations or nationalities. ...
Shortly before 8 a.m. (12 a.m. ET) 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 U.S. military's 28th combat support hospital in the Green Zone, 20 people were dead and 29 wounded, including three U.S. soldiers and three U.S. civilians, Beck said.
