Looters unleashed last year by the US-led invasion of Iraq overran a sprawling desert complex where a bunker sealed by UN monitors held old chemical weapons, according to an American arms inspector's report.
Charles Duelfer's arms teams say all UN-sealed structures at the Muthanna site were broken into. If the so-called Bunker 2 was breached and looted, it would be another case of restricted weapons at risk of falling into militants' hands.
Officials are unsure whether this latest episode points to a threat of chemical attack, since it isn't known if usable chemical warheads were in the bunker, what may have been taken and by whom.
"Clearly, there's a potential concern, but we're unable to estimate the relative level of it because we don't know the condition of the things inside the bunker," said Ewen Buchanan, spokesman for the UN arms inspection agency in New York, whose specialists have been barred from Iraq since the invasion.
Chief arms hunter Duelfer in an e-mail message Friday from Iraq that he was unaware of "anything of importance" looted from the chemical weapons complex. The report his Iraq Survey Group issued on Oct. 6 said, however, that it couldn't vouch for the fate of old munitions at Muthanna.
One chemical weapons expert said even old, weakened nerve agents -- in this case sarin -- could be a threat to unprotected civilians.
The weapons involved would be pre-1991 artillery rockets filled with sarin, or their damaged remnants -- weapons that were openly declared by Iraq and were under UN control until security fell apart with the US attack. They are not concealed arms of the kind US President George W. Bush claimed Iraq had, but which were never found.
In its Oct. 6 report, summarizing a fruitless search for banned weapons in Iraq, Duelfer's group disclosed that widespread looting occurred at Muthanna, 55km northwest of Baghdad, in the aftermath of the fall of the Iraqi capital.
A little-noted annex of the 985-page report said every UN-sealed location at the desert installation had been breached in the looting spree, and "materials and equipment were removed."
Bunker 2 at Muthanna State Establishment, once Iraq's central chemical weapons production site, was put under UN inspectors' control in early 1991 after being heavily damaged by a US precision bomb in the first Gulf War.