VIENNA, Oct 25: Nearly 400 tons of powerful explosives that could be used in conventional or nuclear missiles disappeared from an unguarded military installation in Iraq, the International Atomic Energy Agency said on Monday.

The Iraqi ministry of science and technology informed the IAEA of the disappearance of 380 tons of mainly HMX and RDX explosive materiel on Oct 10, agency spokeswoman Melissa Fleming told AFP, confirming a report in The New York Times.

"It can be used in a nuclear explosion device, for the explosion," she said, adding: "That's why it was under IAEA verification and monitoring" before the US-led invasion of Iraq in March 2003.

The NYT said the materiel could produce bombs strong enough to shatter aeroplanes or tear the buildings apart.

Ms Fleming noted: "From a proliferation standpoint there is a possible application in nuclear weapons, (but) the most immediate concern is the threat of the explosive falling in the wrong hands and being used to commit terrorist acts."

The NYT reported that the explosives disappeared from the sprawling Al Qaqaa facility, which "was supposed to be under American military control but is now a no man's land, still picked over by looters as recently as Sunday."

"White House and Pentagon officials acknowledge that the explosives vanished sometime after the American-led invasion."

After UN weapons inspectors left Iraq under US pressure last year, "our only ability ... to monitor these sites is through satellite imagery. It was very difficult to detect here (from IAEA headquarters in Vienna), because the things were in bunkers," Ms Fleming said.

She said IAEA chief Mohamed ElBaradei would report the matter to the UN Security Council.

Our Washington correspondent adds: Meanwhile, the news prompted Democratic presidential candidate John Kerry to declare that this was "one of the great blunders" of the Bush administration.

US officials told reporters that President Bush's National Security Adviser Condoleezza Rice had been informed of the missing explosives in September. Iraq's interim government had also informed the United States and UN nuclear inspectors that the explosives had vanished.

Senator Kerry said that failure to secure hundreds of tons of explosives now missing in Iraq was "one of the great blunders" of the war by the Bush administration. "Terrorists could use this material to kill our troops (and) our people, blow up aeroplanes and level buildings.

"The unbelievable blindness, stubbornness (and) arrogance of this administration to do the basics have now allowed this president to once again fail the test of being the commander in chief," Mr Kerry told an election rally.