Bush Calls Off Attack on Poison Gas Lab

W A S H I N G T O N, Aug. 20 -- President Bush called off a planned covert raid into northern Iraq late last week that was aimed at a small group of al Qaeda operatives who U.S. intelligence officials believed were experimenting with poison gas and deadly toxins, according to administration officials.

The experiments were being run under orders from a senior al Qaeda official who was providing money and guidance from elsewhere in the region.

U.S. officials familiar with the joint CIA and Pentagon operation said they were concerned they might be dealing with what could have been a budding chemical weapons laboratory.

Intelligence sources said the al Qaeda operatives were under the protection of a small radical Kurdish group called Ansar al Islam. It is a radical Islamic faction closely allied with al Qaeda that operates in a part of northern Iraq controlled by Kurds.

Since the Persian Gulf War, the United States has operated a so-called no-fly zone over much of northern Iraq to protect the Kurds from Saddam Hussein's periodic crackdowns. U.S. officials say they have no evidence Saddam's government had any knowledge of the al Qaeda operation.

Deadly Substance From the Castor Bean

Most of the experiments, sources say, involved a poison called ricin, a byproduct of the widely available castor bean plant.

"It is quite toxic, probably seven times more toxic than phosgene, which was a chemical weapon used in World War I," said Jonathan Tucker, director of the Chemical and Biological Weapons Nonproliferation Program at the Monterrey Institute of International Studies.