American forces in Iraq are chasing down leads from captured Iraqis and documents on possible chemical and biological weapons sites, but as of Monday had not confirmed the presence of any weapons of mass destruction, a senior administration official said. A suspicious plant captured by American troops was still being evaluated, according to the official, who spoke on condition of anonymity.

In Qatar, Gen. Tommy Franks said, "It would not surprise me if there were chemicals in the plant and it would not surprise me if there weren't."

Franks, the U.S. commander, said Monday that some sites suspected of containing weapons of mass destruction are in American control while others are not. "It's a bit early for us to have an expectation of having found" these weapons, he said.

U.S. officials are questioning two captured Iraqi generals about chemical and biological weapons, an American commander in the region said Sunday.

The military also is following up on a cache of documents found by commandos in western Iraq, the Pentagon's top general said.

U.S. Central Command, which oversees the war in Iraq, said in a statement that troops were examining several "sites of interest," but that it was premature to call the plant in Najaf a chemical weapons factory.

Finding deadly chemical or biological weapons would be a coup for the United States, which says its invasion of Iraq is meant to rid Iraq of such weapons.

International opposition to the war, led by France and Germany, has focused on the view that United Nations inspectors should have been given more time to verify Iraq's claims to be free of weapons of mass destruction.

Iraq claims it destroyed all of its chemical and biological weapons and ended its nuclear weapons program shortly after the 1991 Persian Gulf War . U.N. weapons inspectors say those claims are highly suspect - and the United States says they are blatant lies.

American special operations forces found documents in western Iraq that could lead to banned weapons facilities, Air Force Gen. Richard Myers, chairman of the Joint Chiefs of Staff, said Sunday.

Myers said U.S. commandos found the papers along with a cache of millions of rounds of ammunition after a firefight Saturday, and the discovery "might save thousands of lives if we can find out exactly where and what they have."

"I just know that they have some papers that they want to exploit as quickly as possible, and we're going to do that, of course," Myers said.

U.S. Army troops on Sunday secured a 100-acre site in Najaf that could be a chemicals factory that may have made chemical weapons, U.S. officials said. The find, first reported by a journalist from the Jerusalem Post traveling with the Army, could be the first hard evidence of chemical weapons discovered during the war.

U.N. weapons inspectors are not aware of any large-scale chemical sites that could be used to make chemical weapons in Najaf, said Ewen Buchanan, spokesman for the inspectors. However, there are many such dual-use sites elsewhere in the country because of Iraq's petrochemical industry.

The inspectors visited a cement plant in the Najaf area earlier this year to check on its explosives cache but did not report finding anything improper. A team of biological weapons inspectors also visited a university and school in Kufa, a few miles north of Najaf.

Asked at a news conference in Qatar on Sunday about reports of the chemical plant, Lt. Gen. John Abizaid of U.S. Central Command declined comment. He said top Iraqi officers have been questioned about chemical weapons.

"We have an Iraqi general officer, two Iraqi general officers that we have taken prisoner, and they are providing us with information," Abizaid said.

American officials are focusing on the most senior officers among the more than 2,000 captured Iraqi troops in the hunt for chemical and biological weapons. Most of the Iraqi captives are mere foot soldiers who would not know anything about the banned weapons - making the two generals probably the most valuable prisoners in U.S. custody.

Any Iraqis seized in the raids that yielded the documents Myers discussed also would be important prisoners, said Daniel Goure, a military analyst at the Lexington Institute, a Washington-area think tank.

Finding weapons of mass destruction could take a long time, military officials said, since Iraq probably worked hard to hide them.

"You shouldn't think it's going to happen tomorrow," Abizaid said.

PHOTO CAPTION

General Tommy Franks, commander of U.S. Central Command takes a question from a reporter during a news conference in Doha, Qatar, Monday, March 24, 2003 in this image from video. Franks updated the status of the war on Iraq , confirming two U.S. Apache attack helicopter crew members are currently missing in action in Iraq. (AP Photo/APTN)