U.S. counter-terrorism authorities, exploiting a trove of information gleaned from computers and other gear captured with Al Qaeda chieftain Khalid Shaikh Mohammed, raced Sunday to identify individuals who they believe might be poised to launch attacks in the United States.
While interrogators worked urgently to pry information from the terrorist network's operations leader, FBI agents in the United States and CIA operatives overseas ran down leads pulled from computers, computer disks, paper documents, cellular telephones and other electronic paraphernalia seized in a raid near Pakistan's capital, Islamabad.
The joint Pakistani-U.S. raid before dawn Saturday at a home in Rawalpindi netted Mohammed, described by U.S. officials as one of the world's deadliest terrorists and the mastermind of the Sept. 11 attacks, and two other suspected Al Qaeda members.
Late Sunday, U.S. officials said they were trying to ascertain whether one of the men, described as an Egyptian, is Saif Adel, Osama bin Laden's security chief.
"We don't know for sure," said one U.S. official. "The guy's not talking."
Authorities said the seized items may prove to be a breakthrough in the war on terrorism, in that they could contain the names of Al Qaeda members, details of past and present terrorist plots and the locations of "sleeper" cells in the United States and overseas.
Mohammed, they noted, is considered the most important Al Qaeda leader -- more important than Bin Laden -- in terms of reestablishing the terrorist network and overseeing plots to launch attacks. He has been linked to most of Al Qaeda's most devastating terrorist attacks on four continents, dating to the bombing of the World Trade Center in 1993.
But the good news about the trove of information was tempered by recent intelligence reports indicating that Mohammed had been coordinating and planning many attacks in the weeks before his arrest. Some of them appeared ready to be launched against targets in the United States, U.S. officials said.
"There were indications that he was involved in planning attacks [that were] not far away," said one U.S. official, speaking on condition of anonymity.
The official said authorities had identified "several in the United States and elsewhere," based on credible intelligence.
"He was an active fellow," the official said of Mohammed, who records show is a 37-year-old Kuwaiti born to Pakistani parents.
A U.S. intelligence memo dated Feb. 26 and reported Sunday by Newsweek's Web site warned that Mohammed was overseeing an effort to have Al Qaeda sleeper cells in the United States attack suspension bridges, gas stations and power plants in major cities, including New York.
That information came from at least one captured Al Qaeda soldier who knew Mohammed personally, and it was corroborated by other sources, the official said.
In some planned attacks, terrorists would ram tanker trucks into fuel pumps at gas stations, while other attackers would blow up suspension bridges or slash their cables, the official said.
"He indicated that Mohammed would go back to plots that he had previously worked on that had not yet come to fruition, and there was other information from other sources which pointed to the same kind of things that we were hearing from the detainees," the official said.
Asked if U.S. counter-terrorism authorities believed that the plotters were somewhere in the United States, the official said, "We don't know."
After authorities confirmed that the man detained in the guest house of a Pakistani religious leader was indeed Mohammed, they seized on the electronic gear and immediately began trying to extract information, officials said.
By Sunday, U.S. forensic experts had made limited progress in deciphering the jumble of data contained in the documents and computers.
They reported that the data appeared to include "operational detail, names ... including Al Qaeda operatives around the world, including here" in the United States, one federal law enforcement official said.
"It could be the mother lode of information that leads to the inner workings of Al Qaeda," the official said. "How they work, where they work, who they are, what their financial structure is."
But that official and others said they had a short window of opportunity -- a few days at most -- before potentially thousands of Al Qaeda operatives might bore deep underground, disappear or, worse, try to launch attacks out of fear that Mohammed's capture could lead to further arrests.
As a result, the official said: "We are moving quickly on this. We are trying to pinpoint. So the next 48 hours, the next week, we may find ourselves locking some of these guys up."
Officials at the National Security Agency listened attentively to their global array of electronic eavesdropping satellites, waiting for an expected flurry of e-mails and cell phone calls among Al Qaeda members. And authorities watched for the movement of cell members seeking cover, particularly those believed to have been in direct contact with Mohammed.
"It's fair to say that we are alert to all manner of reactions that his detention might spark," said one official. "We will try to exploit that as best we can."
Meanwhile, U.S. counter-terrorism officials and lawmakers were jubilant Sunday in describing Mohammed's arrest.
"This is a very huge event," Rep. Porter J. Goss (R-Fla.), chairman of the House Intelligence Committee, said in an appearance on ABC's "This Week."
Goss, like intelligence officials, did not comment on specifics. But he said the arrest could be considered a success whether or not Mohammed cooperated.
"This is just extremely important, and it's going to lead to other very successful activities very shortly, I'm sure," Goss said.
Asked whether he thought that Mohammed knew the whereabouts of Bin Laden, Goss said: "Yes, I think he does know. And I suspect he has been in contact with him as well."
Mohammed was being held Sunday under extremely heavy guard at an undisclosed location in U.S. military custody.
U.S. officials stressed that Mohammed would not be tortured, because torture is prohibited by both U.S. policy and -- at least for prisoners of war -- by the Geneva Convention.
But, one official said, interrogators were "pushing the envelope" in doing whatever they thought would work in getting Mohammed to talk, noting that potentially thousands of lives were at stake.
"We don't sanction torture, but there are psychological and other ways that we can get most of what we need," Sen. John D. "Jay" Rockefeller IV (D-W.Va.), vice chairman of the Senate Select Committee on Intelligence, said on CNN's "Late Edition."
Several officials said that although they did not know the details, Mohammed was probably undergoing a brutal battery of round-the-clock interrogations, as well as forced sleep deprivation, psychological manipulation, exposure to bitter cold or intense heat, and perhaps even drugs in an effort to break his will.
Pakistani authorities detained Mohammed's two young sons in a raid last September, and one official suggested that the boys could be used as a form of leverage.
Others discounted that scenario, saying that someone who has boasted about being the orchestrator of attacks that killed thousands of people would be unlikely to waver for family reasons.
Authorities conducted a similar interrogation after the captures last year of other top Al Qaeda leaders, including recruiter Abu Zubeida and Sept. 11 co-conspirator Ramzi Binalshibh. But they said the situation with Mohammed was different and far more urgent, given his suspected role in terrorist plots believed to be in their final stages.
In some cases, U.S. officials have been known to transfer detainees to "third-party" countries that engage in torture, particularly Middle Eastern nations, if other methods of gaining information don't work.
"There have been a number of Al Qaeda detainees that we were unsuccessful in getting information from who, once we turned them over to others, started singing like birds," said Vincent Cannistraro, former head of counter-terrorism for the CIA.
For now, U.S. officials want Mohammed in their custody to help them capture Bin Laden and other Al Qaeda leaders.
But they said a far more pressing priority was trying to get Mohammed to help them identify Al Qaeda field commanders and terrorist cells, particularly in the United States.
"No one thinks Khalid Shaikh Mohammed is going to be a willing collaborator. That is why the computer documentation is so important," said Cannistraro, who remains in contact with CIA operatives involved in the current counter-terrorism effort.
"There was enough documentation in the room where he was caught to give them operational leads to members of Al Qaeda in North America," Cannistraro added. "They are trying to exploit these leads immediately. They are working around the clock."
Cannistraro also said late Sunday that the CIA was trying to determine whether the Egyptian captured with Mohammed is Adel, Bin Laden's security chief.
But he said those efforts were hampered by a lack of current photos of the man. Pakistani officials have identified the Egyptian as an important Al Qaeda figure.
Ultimately, officials said, Mohammed's brazen efforts to continue his role as the coordinator of Al Qaeda attacks proved his undoing, in that it helped the CIA and Pakistani authorities track him to the guest house in a fashionable section of Rawalpindi near the military headquarters.
And his reliance on modern tools of communication -- laptops and cell phones in particular -- will be used against him and the Al Qaeda network he spent a decade helping to build, U.S. officials said.
"He needs to communicate, and he needs to communicate with the boss [Bin Laden]," Cannistraro said. "He was reporting and keeping him informed. It gives them a good leg up on getting to him."