Baghdad, Iraq ? U.S. troops raiding a warehouse in the northern city of Mosul uncovered a suspected chemical weapons factory containing 1,500 gallons of chemicals believed destined for attacks on U.S. and Iraqi forces and civilians, military officials said Saturday.

The early morning raid last Monday found 11 precursor agents, “some of them quite dangerous by themselves,” a military spokesman, Lt. Col. Steven Boylan, said in Baghdad.

Combined, the chemicals would yield an agent capable of “lingering hazards” for those exposed to it, Boylan said. The likely targets would have been “coalition and Iraqi security forces, and Iraqi civilians,” partly because the chemicals would be difficult to keep from spreading over a wide area, he said.

Boylan said the suspected lab was new, dating from sometime after the U.S.-led invasion of Iraq in 2003. The Bush administration cited evidence that Saddam Hussein’s government was manufacturing weapons of mass destruction as the main justification for the invasion. No such weapons or factories were found.

Military officials did not immediately identify either the precursors or the agent they could have produced. “We don’t want to speculate on any possibilities until our analysis is complete,” Col. Henry Franke, a nuclear, biological and chemical defense officer, was quoted as saying in a military statement.

Investigators still were trying to determine who had assembled the alleged lab and whether the expertise came from foreign insurgents or former members of Saddam’s security apparatus, the military said.

“They’re looking into it,” Boylan said. “They’ve got to go through it – there’s a lot of stuff there.” He added that there was no indication that U.S. forces would be ordered to carry chemical warfare gear, such as gas masks and chemical suits, as they did during the invasion and the months immediately afterward.

U.S. military photos of the alleged lab showed a bare, concrete-walled room scattered with stacks of plastic containers, coiled tubing, hoses and a stand holding a large metal device that looked like a distillery. Black rubber boots lay among the gear.

The suspected chemical weapons lab was the biggest found so far in Iraq, Boylan said. A lab discovered last year in the insurgent stronghold of Fallujah contained a how-to book on chemical weapons and an unspecified amount of chemicals.

No chemical weapons are known to have been used so far in Iraq’s insurgency.