<font size="6"><center>U.S. Officials Worry About Sleeper Cells</font size></center>
Jul 13, 7:57 PM (ET)
By MARK SHERMAN
WASHINGTON (AP) - The possibility that terrorist "sleeper cells" are working undetected in America is near the top of worries for counterterrorism officials. This concern is brought home by evidence that seemingly ordinary young men carried out the London bombings.
Particularly unnerving is that last week's bombings and those in Madrid last year suggest extremists already in place - in some cases, native-born citizens - can plan and execute an attack without attracting police attention.
The government raised the terror alert to high for mass transit systems after the London attacks. But officials said they have no credible, specific threats of an attack on America.
Even before the attacks on the London mass transit system, FBI Director Robert Mueller said the Madrid bombings "have heightened our concern regarding the possible role that indigenous Islamic extremists, already in the U.S., may play in future terrorist plots."
Some experts caution that there are vast differences between Muslim communities in Europe and the United States. Still, Mueller told Congress in February, "I remain very concerned about what we are not seeing."
The would-be attackers might al-Qaida operatives - sleeper agents who have been here for some time and are awaiting an order - or homegrown terrorists who are influenced, if not directed, by al-Qaida, Mueller said.
British investigators appear to be pursuing leads that suggest the suspected London bombers - at least three of whom are British citizens of Pakistani descent - fall into the latter category.
In his annual assessment of the terror threat, Mueller also said that some converts to Islam could be motivated to undertake attacks.
The Bush administration has moved aggressively against people suspected of training for and plotting attacks, Critics have said the charges have been overblown and unrelated to terrorism in many cases.
The administration has pointed to the convictions of six Yemeni-Americans from Lackawanna, N.Y., who were recruited to a terrorist training camp in Afghanistan shortly before the Sept. 11 attacks as a model in pursuing and prosecuting terrorism suspects. Prosecutors never charged the men with planning terrorist attacks.
In a pending case in Lodi, Calif., a U.S.-born Muslim and his father have been charged with lying to federal agents about his attendance at a terrorist camp in Pakistan in 2003 and 2004. The FBI alleged in an affidavit that Hamid Hayat returned to the U.S. in May intending to wage attacks, but said its agents had found no immediate threat or terrorist activity.
Steven Simon, a national security aide in the Clinton administration, said previously unknown groups of attackers "are coming out of the woodwork" in Europe, where Muslim communities tend to be less prosperous and integrated than they are in the U.S.
"It doesn't look like the kind of infrastructure that exists in Europe has been discovered here," said Simon, a senior Rand Corp. analyst who is co-author of the upcoming book, "The Next Attack."
He said he considers such attacks here unlikely in the near term, but said that could change if the Muslim population becomes as alienated as it is in Europe.
Still, Simon echoed Mueller when said, "It's often said that you don't know what you don't know. Things may be escaping our notice."
Jul 13, 7:57 PM (ET)
By MARK SHERMAN
WASHINGTON (AP) - The possibility that terrorist "sleeper cells" are working undetected in America is near the top of worries for counterterrorism officials. This concern is brought home by evidence that seemingly ordinary young men carried out the London bombings.
Particularly unnerving is that last week's bombings and those in Madrid last year suggest extremists already in place - in some cases, native-born citizens - can plan and execute an attack without attracting police attention.
The government raised the terror alert to high for mass transit systems after the London attacks. But officials said they have no credible, specific threats of an attack on America.
Even before the attacks on the London mass transit system, FBI Director Robert Mueller said the Madrid bombings "have heightened our concern regarding the possible role that indigenous Islamic extremists, already in the U.S., may play in future terrorist plots."
Some experts caution that there are vast differences between Muslim communities in Europe and the United States. Still, Mueller told Congress in February, "I remain very concerned about what we are not seeing."
The would-be attackers might al-Qaida operatives - sleeper agents who have been here for some time and are awaiting an order - or homegrown terrorists who are influenced, if not directed, by al-Qaida, Mueller said.
British investigators appear to be pursuing leads that suggest the suspected London bombers - at least three of whom are British citizens of Pakistani descent - fall into the latter category.
In his annual assessment of the terror threat, Mueller also said that some converts to Islam could be motivated to undertake attacks.
The Bush administration has moved aggressively against people suspected of training for and plotting attacks, Critics have said the charges have been overblown and unrelated to terrorism in many cases.
The administration has pointed to the convictions of six Yemeni-Americans from Lackawanna, N.Y., who were recruited to a terrorist training camp in Afghanistan shortly before the Sept. 11 attacks as a model in pursuing and prosecuting terrorism suspects. Prosecutors never charged the men with planning terrorist attacks.
In a pending case in Lodi, Calif., a U.S.-born Muslim and his father have been charged with lying to federal agents about his attendance at a terrorist camp in Pakistan in 2003 and 2004. The FBI alleged in an affidavit that Hamid Hayat returned to the U.S. in May intending to wage attacks, but said its agents had found no immediate threat or terrorist activity.
Steven Simon, a national security aide in the Clinton administration, said previously unknown groups of attackers "are coming out of the woodwork" in Europe, where Muslim communities tend to be less prosperous and integrated than they are in the U.S.
"It doesn't look like the kind of infrastructure that exists in Europe has been discovered here," said Simon, a senior Rand Corp. analyst who is co-author of the upcoming book, "The Next Attack."
He said he considers such attacks here unlikely in the near term, but said that could change if the Muslim population becomes as alienated as it is in Europe.
Still, Simon echoed Mueller when said, "It's often said that you don't know what you don't know. Things may be escaping our notice."
