BAGHDAD - U.S. commanders said Monday that they had discovered an Iraqi artillery shell last week containing sarin, one of the deadly nerve agents that Saddam Hussein said he had destroyed before the war began last year.
The shell, which had been fashioned into a homemade bomb, was discovered by an American convoy as it made its way through Baghdad on Saturday, the officials said. Two American weapons experts suffered minor exposure to the nerve agent when they tried to defuse the shell, but they were not seriously harmed, the officials said.
The shell appeared to have been manufactured before the Persian Gulf War in 1991, officials said, adding that it was not clear that the insurgents who planted it knew it contained sarin.
The discovery appears to offer some of the most substantial evidence to date that Hussein had not destroyed all of the banned chemical agent, as he claimed before the American-led invasion last year. It provides some solace, and possibly fresh leads, to the American teams that have been conducting an otherwise fruitless search for the weapons for more than a year.
If confirmed in subsequent testing, the discovery would be the first evidence of a banned weapon in Iraq since the war began. The Bush administration based its case for the war on the existence of such weapons.
The Bush administration's belief that Hussein continued to maintain stocks of such banned weapons, including chemical and biological agents, was the primary justification put forward for invading Iraq in March 2003. American inspectors scouring the country since April 2003 have found little evidence that Hussein maintained such weapons or a program that could produce them.
Defense Secretary Donald Rumsfeld reacted cautiously to the discovery Monday, saying that so far only a field test had found traces of sarin and that more extensive tests were necessary.
Over the past year, field tests conducted by soldiers in Iraq have produced initial results indicating the presence of nerve agents, only to be proved false after more sophisticated testing.
In the months before the war, President Bush, citing American intelligence estimates, asserted that Hussein had the materials to produce as much as 500 tons of sarin, mustard and VX nerve agent.
Hussein's government was believed to have produced several hundred tons of sarin in the 1980s. Sarin, an odorless, colorless gas that brings agonizing death to its victims by attacking the nervous system, was among the weapons used in large quantities during the Iraqi military's attack on the Kurdish town of Halabja in 1988. More than 5,000 people are believed to have died in that attack, and more than 65,000 people were injured.
Sarin was also among the nerve agents used by the Iraqi army against Iran in the 1980s, when thousands of Iranian soldiers were killed with such unconventional weapons.
Hussein declared after the 1991 Persian Gulf War that his country had made a small number of weapons known as binary nerve agents, so called for the dual-chambered shell in which their components are stored. But it was not until much later, after the defection in 1995 of Hussein's son-in-law, Hussein Kamel, that Iraqi officials admitted that they had produced sarin.
Brig. Gen. Mark Kimmitt, the deputy director for operations in Iraq, said he believed that insurgents who planted the explosive did not know it contained the nerve agent. The 155mm shell did not have markings to indicate it contained a chemical agent.
He said a U.S. military convoy discovered the round, which had been rigged as an explosive device. A detonation took place before soldiers could make the bomb inoperable, producing "a very small dispersal of agent."
Kimmitt said the military was searching the area for more such shells. "There may be more out there," he said.
Hans Blix and David Kay, two former U.N. weapons inspectors, suggested Monday that the shell the Army discovered was likely to be a stray scavenged by militants from a weapons dump.
Kay, the former head of U.S. weapons inspectors in Iraq, said it appears that the shell was one of tens of thousands produced for the Iran-Iraq war, which Hussein was supposed to destroy or turn over to the United Nations. In many cases, he said, Iraq did comply.
"It is hard to know if this is onethat just was overlooked - and there were always some that were overlooked, we knew that - or if this was one that came from a hidden stockpile," Kay said. "I rather doubt that, because it appears the insurgents didn't even know they had a chemical round."
While Saturday's explosion does demonstrate that Hussein hadn't complied fully with U.N. resolutions, Kay also said, "It doesn't strike me as a big deal."
- Information from the New York Times, Associated Press, Cox News Service and Scripps Howard News Service was used in this report.SARIN AT A GLANCE
Some facts about sarin:
WHAT IT IS: Originally developed in Germany in 1938 as a pesticide, sarin is a clear, colorless and tasteless liquid that can evaporate into an odorless gas. It is also known as GB.
HOW PEOPLE ARE EXPOSED: Once sarin is released into the air, people can be exposed through skin or eye contact, or breathing air that contains the chemical. It can be used to poison water or food.
WHAT IT DOES: In large enough doses, sarin causes convulsions, paralysis, loss of consciousness and potentially fatal respiratory failure. In smaller doses, people usually recover completely. Symptoms include runny nose and watery eyes, eye pain and blurred vision, drooling, rapid breathing and drowsiness.
ANTIDOTE: The antidote for a lethal amount is a shot that includes the drug atropine, which must be injected into the thigh within minutes.
PRIOR KNOWN USE: The Aum Shinrikyo cult used sarin in 1995 attacks in the Tokyo subway system that killed 12 people.
PRIOR LINK TO IRAQ: Iraq first told U.N. inspectors it had made 812 tons of sarin, then said it had made 790 tons. Iraq also produced binary weapons: bombs carrying two separate chemicals that when combined in an explosion, produce sarin. Iraq acknowledged making thousands of rockets, artillery shells and bombs containing sarin. It used the chemical during its war with Iran in the 1980s and is believed to have used it against Kurdish Iraqi civilians.
- Source: Associated Press