BAGHDAD, Iraq—A probable suicide bomber used a large flatbed truck packed with as much as 1,500 pounds of military munitions, including a single 500-pound bomb, to blow up the U.N. headquarters in Baghdad, the FBI agent in charge of the investigation said Wednesday.
Special Agent Thomas Fuentes, the FBI's top official in Iraq, said human remains were found among the wreckage of the vehicle, a Russian-made cargo truck, indicating that Tuesday's bombing probably was a suicide attack. The blast was so powerful that a bumper believed to be from the truck was found more than 500 yards away.
No group claimed responsibility, and Fuentes said he was unaware of any threats made to the U.N. compound beforehand. He said it was too early to tell whether the attack was carried out by Iraqi guerrillas loyal to deposed dictator Saddam Hussein or foreign terrorists. However, suicide truck bombings have long been a favored tactic of Islamic militants.
A large amount of military munitions in Iraq are "readily available to any number of groups," Fuentes said.
U.S. military engineers worked late Wednesday with a backhoe and military bulldozer to clear away large pieces of concrete and twisted metal, while soldiers searched by hand for victims. Hopes dimmed that any more survivors would be found.
Fuentes said it would take at least a couple of days to clear the rubble, find any remaining bodies and collect whatever evidence was there.
The bombing killed more than 20 people, including Sergio Vieira de Mello, the top U.N. envoy in Iraq, and wounded more than 100.
Fuentes said accurate figures on casualties were difficult to pin down. Some U.N. personnel still were missing, and officials were having a difficult time accounting for all employees because the wounded were taken to a number of hospitals.
The devastating blast was the worst attack ever on a U.N. facility, and the deadliest in Iraq since major combat in the U.S.-led war that toppled Saddam ended more than three months ago. The bombing came just 12 days after a car bomb at the Jordanian Embassy killed 19 people and wounded more than 60.
The U.N. bombing further eroded Iraqis' faith in the ability of the U.S.-led troops to bring security. That faith already had been undermined as anti-American militants engaged in acts of terrorism and as more civilians died in the crossfire.
On Wednesday one U.S. soldier and an American contractor working as an interpreter were killed in hostile actions, U.S. Central Command said.
The soldier, with 3rd Corps Support Command, died when his flatbed transporter was hit with automatic weapons fire in Diwaniyah, in southern Iraq, where such attacks have been rare. The interpreter died in Tikrit when troops came under fire from rocket-propelled grenades and small arms.
At least 69 U.S. and coalition soldiers have been killed in combat in Iraq since President Bush declared major combat operations over May 1.
At a news conference Wednesday in Stockholm, Sweden, U.N. Secretary General Kofi Annan said the United Nations would review its security procedures, but wouldn't end its mission in Iraq.
"We will persevere. We will continue. It is essential work. We will not be intimidated," Annan said.
Foreign U.N. staff members who worked at the compound were told to stay in their hotels Wednesday. While some contemplated leaving, others vowed to stay.
"We know what is happening here," said a Kenyan staffer, who asked not to be named. "We know who the target is. People say we're a soft target, but this was really directed at the Americans."
At some U.N. facilities, such as the World Health Organization, guards in flak jackets checked vehicles for bombs and made drivers park farther away.
Fuentes, the FBI agent, said investigators recovered portions of the bombing vehicle, including the engine, vehicle registration number, license plate and bumper, and would begin trying to track down who owned the truck and where it came from. Sample swabs from the wreckage and from human remains in the vehicle will go to FBI headquarters in Washington for analysis.
The FBI team includes experts who worked on the U.S. embassy bombings in Africa in 1998 and several bombings in Saudi Arabia, all of which are believed to have been carried out by al-Qaida.
Fuentes said the Soviet-era military munitions on the truck included artillery shells, mortar rounds and one 500-pound bomb designed to be dropped from an aircraft. Investigators didn't know how they were detonated because they haven't found the triggering device.
Most Iraqi military weapons and munitions were supplied by the former Soviet Union from the 1960s through the 1980s, until U.N. sanctions banned arms exports to Iraq after it invaded Kuwait in 1990.
Initial reports by Iraqis and some U.S. officials said a cement truck smashed through the gate or through a cement-block security wall. Fuentes said the truck never entered the compound, but exploded on an unguarded road adjacent to the wall, about 10 yards from the building. The blast gouged a 6-foot-deep crater in the ground and collapsed a corner of the building where de Mello's office and a humanitarian assistance center were.
Fuentes said rescue efforts and attempts to collect evidence were hampered by the danger of unexploded ordnance in the wreckage. An unexploded Soviet-made hand grenade, with its pin sheared off, was found Tuesday, he said.
(Knight Ridder Newspapers correspondents Hannah Allam and Ken Dilanian contributed to this report from Baghdad.)
(c) 2003, Knight Ridder/Tribune Information Services.
PHOTOS (from KRT Photo Service, 202-383-6099): USIRAQ
GRAPHICS (from KRT Graphics, 202-383-6064): 20030820 UN attacks, 20030820 USIRAQ bomb scene and 20030820 UN staff move