Baiji, Iraq ? U.S. soldiers on Saturday found 14 barrels of chemicals in a vast weapons storage area in north-central Iraq, and three initial tests indicated that they contained a deadly mixture of cyclosarin nerve agent and mustard gas.

Previous finds of suspect chemicals in Iraq have turned out to be false alarms, and a Pentagon spokeswoman Saturday said defense officials had no conclusive evidence that the barrels contained chemical weapons. She said samples from the barrels would be sent to the Aberdeen Proving Grounds in Maryland for further testing, a process that could take a week. An international team of chemical weapons experts headed to the site from Baghdad to conduct further tests today.

But the fact that the barrels were found next to a mobile laboratory in a munitions dump makes them more suspicious, and if further tests confirm that they contain chemical weapons, it would provide the long-awaited evidence that Iraq was hiding chemical weapons, as the Bush administration charged in justifying the need for war.

The tan barrels were found in a 3.5-square-mile storage area that also contained missiles, missile parts, gas masks, protective gear, a stripped mobile weapons laboratory and large storage containers covered by camouflage netting. The area is two miles east of the town of Baiji in the Jabal Makhul, low, wind-worn mountains about 25 miles north of Saddam Hussein’s hometown of Tikrit.

The barrels were on the ground next to a mobile laboratory that looked like a 1970s Russian truck with a cube on the back that was filled with sinks, a fermenter and other equipment. It had been stripped bare, apparently by looters. Lt. Col. Ted Martin, the commander of the 10th Cavalry unit that tested and secured the barrels, said the mobile lab had charts showing dosage amounts.

Lt. Victoria Phipps of Sherwood Ark., who heads the chemical reconnaissance team from the 10th Cavalry at the site, said three tests verified the presence of cyclosarin, a nerve agent, as well as a blistering agent, most likely mustard gas in liquid form, mixed together in a toxic slurry.

The tests, she said, are 98 percent accurate.

“There was so much intensity in that area it was hard to test further,” she said. “The levels were very high.”

Cyclosarin is part of the family of organophosphate chemicals, which are also used in insecticides. Exposure to a lethal dose of sarin or cyclosarin leads to loss of muscle control, paralysis and convulsions. Death can occur in minutes. Low and medium exposure can result in nausea, dimness of vision and other symptoms that can last from days to weeks.

Officers at the site where the barrels were discovered said the results of the initial tests and the proximity to other types of munitions seemed to indicate a high probability that the chemicals were intended as weapons, not for benign purposes such as pesticides.

“It’s the worst-case scenario in a can,” said Martin.

Special forces soldiers discovered the barrels on Friday afternoon, nestled in the low mountains near a tributary of the Tigris River. The team ran a quick test and determined the presence of a blister agent.

Team members decontaminated themselves, left the area and called in the 10th Cavalry. Unable to find the barrels on Friday night, soldiers from the 10th Cavalry resumed the search on Saturday morning and found them on the ground.

The 10th Cavalry team, wearing protective gear, lifted one barrel, which soldiers said was about three-quarters full, and opened it. They used baling wire to remove a sample and placed it on a chemical sensor called the M-21 Rascal. The tester uses a mobile mass spectrometer, which ionizes chemical agents to determine their mass. It then uses a computer to compare the mass to that of 68 known chemical weapons agents.

Few locals were seen in the area where the weapons were found. But one man interviewed by the Army said that an Iraqi officer appeared at the site shortly after the war began. When the local man asked him why he was there, the officer said it was too dangerous a place for anyone to come looking for him.

As of Saturday night, U.S. soldiers had blocked off several square miles of the site and a decontamination team and doctors had arrived.

Martin and his men also began searching for more sites.

“I suspect this one here is not the only one,” he said.