WASHINGTON — Khalid Shaikh Mohammed, who authorities now believe conceived the Sept. 11 attacks, apparently met with the terrorist plot's chief suicide hijackers in 1999 in Hamburg, Germany, U.S. intelligence officials said Wednesday.
A senior intelligence official said "several different sources" had placed Mohammed at the Hamburg apartment that was used for meetings by three of the Arabs who are believed to have piloted the hijacked planes, as well as by several others implicated in planning and funding the operation.
The new intelligence may help to solve one of the major puzzles about Sept. 11--who outside the hijacking teams helped coordinate their actions and provided the link to senior Al Qaeda leaders. Mohammed is now believed to have filled at least part of that pivotal role.
The intelligence official said interrogation of Al Qaeda prisoners captured in Afghanistan and elsewhere, as well as "tracing of documents" and other raw intelligence collected in recent months, indicated that Mohammed was one of the few people with direct knowledge of the recruiting, training, funding and other operational details behind the attacks.
"The number of people central to this plan was very small," said the official, who spoke on condition of anonymity. "He was one of them."
Although Mohammed was little known to the public until this week, officials said he has now been tied to the 1993 bombing of the World Trade Center, a foiled 1995 attempt to bomb 12 U.S. airliners over the Pacific, the 1998 bombings of U.S. embassies in Tanzania and Kenya, and the Sept. 11 attacks on New York and the Washington area.
"He is the Forrest Gump of Al Qaeda," a Bush administration official said. "He has more of a presence in some of their plots than we had previously known."
The official said counter-terrorism experts had focused their attention over the last two years chiefly on the more high-profile Abu Zubeida, the Al Qaeda operations chief who was captured in March in Pakistan.
"Khalid Shaikh Mohammed had been quiet and had stayed off the airwaves," the official added. "In hindsight, I don't think people appreciated how important a player he had become in the Al Qaeda hierarchy. We are learning all that now."
Mohammed was indicted by a U.S. court in 1996 for his alleged role in the airliner plot, but the federal arrest warrant was sealed so he wouldn't know that authorities were scouring the globe for him.
Officials said it is still unclear precisely when Mohammed visited Hamburg, or which of the hijackers he met there. Mohamed Atta, Marwan al-Shehhi and Ziad Jarrah--who are believed to have piloted three of the hijacked planes--lived in the northern German city for most of 1999.
Atta's two roommates--Ramzi bin al-Shibh and Said Bahaji--also are suspected of participating in the plot. Unable to get a U.S. visa, Bin al-Shibh helped wire tens of thousands of dollars to the hijackers and to Zacarias Moussaoui, who was arrested before Sept. 11 and later was charged with conspiracy. Investigators have said Moussaoui was supposed to take Bin al-Shibh's place as the 20th hijacker.
Mohammed's whereabouts are unknown, although officials hinted that at least one unsuccessful covert operation was launched to capture him in the late 1990s in the Middle East.
"We don't have a real good bead on where's he been," another intelligence official said. "Obviously we'd love to talk to him."
U.S. authorities are offering a reward of as much as $25 million for information leading to his capture. He is believed to be in Afghanistan or Pakistan.
Mohammed initially was known as an accomplice to Ramzi Yousef, the convicted mastermind of the first World Trade Center bombing in 1993 and of a 1995 plot to detonate bombs aboard 12 U.S. airliners over the Pacific Ocean.
According to the 1996 U.S. indictment, Yousef, using the name Dr. Adel Sabah, rented an apartment in the Tiffany Mansion condominium building in the San Juan section of Manila, the capital of the Philippines, in August 1994.
In the next two months, Yousef and Mohammed lived there and used the location to mix chemicals for explosives. They were also in possession of "modified timing devices," the indictment said.
On Dec. 1, 1994, they and a number of other men detonated an explosive device at Manila's Greenbelt Theater. That was a test, authorities say, for the explosive device placed 10 days later on Philippine Airlines Flight 434 from Manila to Tokyo. The small bomb exploded in midair, according to the indictment, killing passenger Haruki Ikegami.
The plot was uncovered in January 1995 when Mohammed's "bomb factory" caught fire and authorities searching Yousef's computer found detailed plans to blow up the airliners. Abdul Hakim Murad, a commercial pilot who wanted to hijack planes, and Wali Khan Amin Shah, a suspected associate of Osama bin Laden, were captured and convicted in the plot along with Yousef.