FBI and CIA experts on Monday examined computers, disks, cell phones and documents recovered from the Pakistani hideout of suspected Sept. 11 mastermind Khalid Shaikh Mohammed, hoping to uncover imminent terrorist plots by Al Qaeda.
In addition to his capture on Saturday, government officials said authorities had caught Mohammed Omar Abdel-Rahman, a son of the blind Egyptian sheik accused of inspiring the 1993 bombing of the World Trade Center.
The younger Abdel-Rahman was caught several weeks ago in Quetta, Pakistan, the officials said, speaking on the condition of anonymity. Pakistani officials have suggested the Quetta arrest helped lead authorities to Khalid Shaikh Mohammed, although American sources disputed that.
Officials also said they believe they have captured a suspected financier of Sept. 11. The financier, whose nationality was uncertain, was captured with Mohammed.
Mohammed was questioned Monday by U.S. authorities seeking information about safe houses and hideouts used by the Al Qaeda terror network, a Pakistani intelligence official said. Mohammed's exact whereabouts were unclear.
He had been plotting attacks against targets in the United States and Saudi Arabia in the weeks before his capture, U.S. counterterrorism officials contended.
Such attacks might have been against commercial or other lightly defended civilian targets, officials said, although they acknowledged they did not know whether Al Qaeda targets had been selected.
Intelligence about Mohammed's activities led in part to the orange alert that lasted most of February, Homeland Security Secretary Tom Ridge said.
"Some of the concerns we had that caused us to raise the threat level were attributable to the planning he was involved in," Ridge said. "There were multiple reasons that we raised the threat level and his relation to one of the plot lines was one of the several."
Ridge declined to discuss specifics but said the threat level was lowered last week because later information showed that plans for attacks had been disrupted and were less likely to occur.
Authorities recovered a huge amount of information about Al Qaeda at the house in Pakistan where Mohammed and two others were arrested early Saturday, a senior law enforcement official said Monday.
Recovered at the home in Rawalpindi were computers, disks, cell phones and documents. Authorities believe the materials will provide names, locations and potential terrorist plots of Al Qaeda cells in the United States and around the world.
Mohammed also was believed by U.S. officials to have details about the group's finances.
He was captured as he slept early Saturday. Pakistani Ahmed Abdul Qadus and the unidentified financier were also detained.
White House spokesman Ari Fleischer said, "We are hoping that this will lead to substantial additional information on Al Qaeda, on Al Qaeda's plans and Al Qaeda's operations."
Officials expressed concern that Al Qaeda cells could accelerate plots in the United States and elsewhere rather than run the risk of being captured. Or cell members might also go into hiding, believing their security was compromised by Mohammed's capture.
Mohammed is suspected of trying to send deputies into the United States at least twice since Sept. 11, officials said.
"We are obviously always mindful of the need to be vigilant and to move as quickly as possible to frustrate anything that's ongoing in terms of potential terrorist threats," said Michael Chertoff, chief of the Justice Department's criminal division.
Mohammed, in his late 30s, is perhaps the most senior Al Qaeda member after Usama bin Laden and his deputy, Ayman al-Zawahri.
He is alleged to have organized the Sept. 11, 2001, terror attacks, and was linked to a 1995 plot to bomb trans-Pacific airliners and crash a plane into CIA headquarters and to the 1993 World Trade Center bombing. He also has been tied to the April bombing of a synagogue in Tunisia, which killed 19 people, mostly German tourists.
As for the separate capture of the younger Abdel-Rahman, government officials said he ran a training camp in Afghanistan before the Sept. 11 attacks. He was considered a senior Al Qaeda operative, perhaps one tier below Mohammed.
He is known as Asadullah, "the Lion of God." His father, Omar Abdel-Rahman, is in a U.S. prison for a 1994 plot to bomb landmarks around New York City. Another son of the blind sheik, Ahmad, was captured in Afghanistan in late 2001.
The Associated Press contributed to this report.