U.S. intelligence agencies detected signs that Iraq may be moving material or equipment out of a suspected biological weapons facility near Baghdad, officials said Wednesday.

Some intelligence analysts believe the movements indicate an effort by Iraqi President Saddam Hussein to disperse the items in anticipation of possible American military strikes, the officials said.

The movements were reported first in the Wednesday editions of the Washington Times.

U.S. officials who spoke on condition of anonymity said spy satellites spotted trucks at the Taji complex, which includes the suspected biological weapons facility as well as a missile production plant.

The purpose of the truck activity was not entirely clear, the officials said, but it appeared they were moving equipment or materials out of, rather than into, the facility, which is about six miles northwest of Baghdad. The officials cautioned that the intelligence is subject to different interpretations.

Other officials said the presence of trucks at a single weapons site probably means little, and said they have not observed any significant increase in activity at other suspected weapons of mass destruction sites around Iraq.

United Nations weapons inspectors determined several years ago that Iraq had produced botulinum toxin, which causes botulism, at that facility. Iraq admitted to the United Nations that it had made 400 liters of botulinum toxin there, but it now insists it has no biological, chemical or nuclear weapons.

U.N. inspectors also found 6,000 empty canisters at Taji that were designed to be filled with chemical weapons for use on 122mm rockets. U.N. inspections ended in 1998; in December of that year, U.S. and British air strikes targeted Taji and other military facilities in and around Baghdad.

Taji also was struck by U.S. bombs during the 1991 Gulf War.

Anthony Cordesman, an Iraq expert at the Center for Strategic and International Studies, said U.S. intelligence experts believe Iraq rebuilt the missile production facility at Taji after the 1998 attacks.

In stating that Iraq poses a threat to the United States and its allies, President Bush has cited Saddam's pursuit of chemical, biological and nuclear weapons in defiance of its disarmament pledge after the Gulf War. Bush has vowed to achieve "regime change" in Iraq, although he says he has not approved a war plan.

Two weeks ago, Defense Secretary Donald H. Rumsfeld told reporters it was "safe to say" that Iraq has developed mobile biological weapons laboratories.

"They move around a lot of things to avoid detection or, if not detection, at least to avoid having them attacked," he said.