A US officer has claimed thousands of vials of unidentified liquid and powder as well as manuals on chemical warfare have been found in two locations near the Iraqi capital Baghdad.
The find, if independently verified, would legitimise US claims that Iraq may launch a chemical attack on Coalition troops.
But Captain Kevin Jackson told Reutersnews agency that it was "unclear at this point what the vials contain and we're sending a team of experts to examine them."
The plant itself, which was shown on US military maps as including underground storage facilities, was south of the southern suburban town of Latifiya.
Separately, Brigadier General Vincent Brooks told a news briefing at US Central Command in Qatar that special forces in Iraq's western desert had found what they claimed to be a training school for handling chemical warfare.
But Lieutenant-Colonel Vincent Quarles, of the engineers brigade of the 3rd Infantry Division, said a Sensitive Site Team was being sent to examine the liquid and powder.
"I have to emphasise that we don't know what this is. There's something there, but the specialists will have to determine that [what it is]," he said.
Earlier, US military sources said there is now little threat of an Iraqi chemical or biological attack against Coalition forces.
Agencies