Thousands of chemical suits found at Iraqi positions, gas masks abandoned in trenches.

The items, strewn across the desert road to Baghdad, could be clues that Saddam Hussein's Republican Guard may be plotting to unleash a deadly chemical strike.

Or they could be the precautionary equipment of a well-supplied army battling the world's mightiest military.

While the United States believes Iraq has chemical and biological weapons, there is no way to know whether Saddam would unleash them. He didn't during the 1991 Gulf War -- when, it is known for certain, he possessed them.

"They know very well that the coalition forces don't have chemical weapons with them so the only reason the Iraqi troops would have that kind of equipment is because they plan to use the weapons themselves," said Terence Taylor, who led U.N. weapons inspections in Iraq in the 1990s. "There is really no other reason for fighting forces to wear special equipment."

Coalition military commanders, expecting Iraq to use biological or chemical weapons, say they are prepared for such an attack and are busily trying to find any stocks of the deadly weapons.

So far they haven't found the weapons, but several new signs are hard to ignore.

In the city of An Nasiriyah, Marines who secured a hospital being used as a military staging area for Iraqi paramilitary forces found over 3,000 chemical suits with masks, Iraqi ammunitions and military uniforms, the U.S. Central Command announced. The Marines also found a T-55 tank on the compound.

And at the city's Tallil air base, U.S. forces sealed off 36 bunkers earmarked as potential sites for weapons of mass destruction.

Iraq admitted storing 6,000 artillery shells filled with mustard agent at a nearby ammunition depot in 1991. The U.S. military, which occupied the air base and the ammunition depot during the first Gulf War, concluded that it was unlikely chemical or biological weapons were stored on the air base at the time.

On Monday, Marines near the Iraqi navy port of Az Zubayar reported finding abandoned Iraqi military gear, including chemical suits.

Elsewhere, Iraqi troops who fled their positions left behind bundles of unused gas masks.

Still, the rush to prove the existence of weapons the United States says it went to war to dismantle, can lead to mistakes.

On Tuesday a senior defense official acknowledged that U.S. military investigators found no evidence that chemical weapons have been made in recent years at a plant secured by U.S. troops in southern Iraq over the weekend.

The weekend captures of the site, a cache of documents and two Iraqi generals thought to have knowledge of weapons of mass destruction raised the possibility that American forces had begun to find banned weapons.

U.S. officials have repeatedly warned that Iraq was more likely to use chemical or biological weapons against coalition troops the closer they get to Baghdad.

"I would expect that they would hold their most valuable treasures close to their heart," Air Force Maj. Gen. Victor Renuart said in Qatar. "And I think as we get closer to Baghdad we will see more of those sites that we will continue to exploit."

"We have continued to develop information that we found and to interview key leaders that we've detained on the battlefield and are developing that information to lead us to more sites," he said.

Secretary of Defense Donald Rumsfeld was more reserved Monday, saying intelligence "scraps," suggested that "the closer that coalition forces get to Baghdad, the greater the likelihood that some command and control arrangements have been put in place," to use chemical weapons. "But whether it'll happen or not remains to be seen."

Gen. Richard Myers, chairman of the Joint Chiefs of Staff, said the U.S. military had its own plan to address such an attack but he would not reveal details.

U.S. officials say they believe Iraq's chemical weapons are under the control of the Republican Guard, Saddam's best-trained and most loyal troops. A large part of those forces is concentrated in the southern part of Baghdad.

Some of Iraq's chemical arsenal, officials say, could be loaded onto artillery and rockets that have a range of about a dozen miles or less.

Pentagon officials who discussed the chemical weapons issue on condition of anonymity said it was unclear what rank of Iraqi officers had been authorized to order the use of chemical weapons. Officials said it was doubtful the chemical authority went as low as company-level commanders, who are usually at captain's rank.

Coalition troops awaiting invasion orders have chemical protection gear and equipment that can detect chemical agents up to three miles away. American tanks and armored vehicles have filters designed to keep the troops inside safe from the deadly agents. Anticipating the possibility of chemical combat, U.S. troops have trained extensively on operating in a contaminated environment.

U.S. and British officials say Iraq has stocks of chemical weapons, including the deadly nerve agents sarin, cyclosarin, mustard gas and VX. Iraq insists that it destroyed its stockpiles after 1991 but weapons inspectors were never able to verify those claims.

If Saddam does retain the weapons, U.S. officials believe he could use them to put down an internal uprising, slow an American onslaught or keep U.S. forces out of a particular area.

A chemical attack against Iraqi civilians could bog down U.S. troops by creating a humanitarian crisis that American forces couldn't ignore.

But Taylor and others believe Saddam's government will use chemical or biological weapons only as a last resort.

"Once they use them, the whole world community would turn against them and everyone would say the Americans and British were right. Even the French have said they would join the coalition if chem-bio was used."