LONDON ø The International Atomic Energy Agency has reported that several hundred tons of conventional explosives have gone missing from an Iraqi military facility.

But NBC reported that when U.S. forces arrived at the Al Qaqaa base on April 10, 2003, the explosives were already missing.

The IAEA said it was informed by the Iraqi government that 342 tons of high explosive material have disappeared since 2003. The agency said the material was taken by looters who exploited the lack of security at government facilities, Middle East Newsline reported.

"The Iraqis told the agency the materials had been stolen and looted because of a lack of security at governmental installations," an IAEA statement said. "We do not know what happened to the explosives or when they were looted."

Later, agency officials said the explosives were taken from the former Iraqi military base at Al Qaqaa, about 50 kilometers south of Baghdad. They said the explosives included HMX and RDX, employed for building demolition, production of missile warheads and detonation of nuclear weaponry.

HMX and RDX have been also termed key components in such plastic explosives as C4 and Semtex. Iraqi insurgents, particularly those loyal to Abu Mussib Al Zarqawi, have used plastic explosives in scores of car bombings in Iraq over the last 16 months.

"The explosives in question are given as: HMW [195 tons], which had been under IAEA seal; and RDX [141 tons] and PETN [six tons], both subject to regular monitoring of stock levels," an letter from IAEA director-general Mohammed El Baradei to the Security Council said. "The presence of these amounts was verified by the IAEA in January 2003."

The IAEA said it had waited more than two weeks until the announcement of the missing explosives. An agency spokeswoman, Melissa Fleming, said the agency had hoped that the HMX and RDX would be recovered.

The agency informed the U.S.-led coalition on the disappearance of the explosives on Oct. 15. The letter said the explosives had been missing from Al Qaqaa since April 2003.

Al Qaqaa was placed under U.S. military control in 2003 after the fall of the Saddam Hussein regime. But the sources said the United States did not deploy sufficient manpower to secure the facility.

"We, from the very beginning of Operation Iraqi Freedom, did everything we could to secure arms caches throughout the country," State Department deputy spokesman Adam Ereli said. "But given the number of arms and the number of caches and the extent of militarization of Iraq, it was impossible to provide 100 percent security for 100 percent of the sites, quite frankly."

In February 2003, the IAEA warned that since 1999 the Saddam regime had transferred the HMX stockpile under agency supervision to other areas of Iraq. Despite the downfall of the Saddam regime, the agency has not been operating in Iraq and the agency did not rule out that the explosives were seized by hostile forces.