That is a source of major frustration at the CIA, which a few years back identified at least 40 people that it wanted to kill, capture or question about their suspected involvement in Al Qaeda's weapons program, Quillen and others said. They said at least half of those suspects remain at large.
Abu Khabab's ties to terrorism date to at least the mid-1980s, when he was a prominent member of the Egyptian Islamic Jihad organization led by Ayman Zawahiri, who merged the group with Al Qaeda. Over the years he has trained hundreds of fighters at Al Qaeda's camps on how to use explosives, poisons and rudimentary chemical weapons, according to FBI documents.
Educated in Egypt as a chemical engineer, Abu Khabab has no formal training in biological or nuclear weapons, intelligence officials say. But he has ended up in charge of the weapons program at least in part because some operatives believed to be more knowledgeable about biological and nuclear weapons have been captured or killed.
Abu Khabab was described by several intelligence officials as a cranky, showboating self-promoter as well as one of its top explosives experts. He has had a stormy relationship with the two top Al Qaeda leaders, Osama bin Laden and Zawahiri, and their top command, in part because of his ego and independent streak, those current and former intelligence officials said.
Nevertheless, Zawahiri tapped Abu Khabab in 1999 to head an unconventional weapons program code-named "Al Zabadi," Arabic for fermented milk. Within months, he had made "significant progress," according to Al Qaeda computer files found after the U.S.-led invasion of Afghanistan.
U.S. authorities found materials at the Darunta complex and elsewhere in Afghanistan that showed that Al Qaeda was aggressively pursuing weapons of mass destruction, including nuclear and biological devices, and that it was only a few years away from developing an anthrax weapon. By 2002, Abu Khabab is believed to have fled to Chechnya or the Pankisi Gorge region in Georgia to resume training militants in the use of chemical weapons, before ending up in Pakistan.
In December 2002, Al Qaeda allegedly dispatched a strike team to New York to use a device called a mubtakkar -- or "invention" -- to disperse cyanide gas in subway cars, potentially killing dozens of people, the senior intelligence official said. Several officials said they suspect Abu Khabab played a role in its development.
