WASHINGTON -- The attacks in London yesterday appear to be the work of an Al Qaeda offshoot, and could provide further evidence that the organization responsible for the Sept. 11 attacks is steadily morphing into a collection of largely independent groups, US intelligence officials and specialists on terrorism said.
Yesterday's bombings, as well as the Madrid commuter train attacks in March 2004, also signal how the global movement of Islamic extremists is planting new roots and terror cells in Europe's large Muslim community, the officials and experts said. They warned that the new cells, whose members can move freely in their communities and within Europe, present a new challenge to antiterror efforts that have focused largely on foreign groups.
US and European intelligence services are monitoring a more pronounced level of radicalization among young Muslim men in Europe, they said, particularly in the wake of the Iraq war, which has drawn in hundreds of European Muslim fighters, according to US military estimates.
Even with much of the Al Qaeda leadership either dead or captured, these new affiliates can continue a holy war against the West with relatively low-tech but deadly attacks such as yesterday's subway and bus bombings.
''I am in the 'homegrown' camp as opposed to the 'cell-dispatched-by-Osama-bin-Laden-from-a-cave,' " said Steven Simon, a former counterterrorism official in the Clinton White House and a senior analyst at the government-funded Rand Corp. ''Madrid as a model is pretty seductive," he added of the bombings in the Spanish capital, which killed 191 people. They were planned by Spanish citizens and by residents of North African descent.
The attacks in London, which killed at least 37 people and wounded 700, displayed the hallmarks of an Al Qaeda-type operation, US intelligence officials said.
But the relative simplicity of the attacks suggests that they were not carried out under the direct orders of bin Laden or his deputies, according to the officials, but by a group operating on its own.
Bin Laden's group planned the 9/11 attacks in the United States years in advance, and trained and dispatched the hijackers. Officials say he may now be believe he is now trying to mount more spectacular attacks to top 9/11, which killed 3,000 people.
''The central question is whether it is an Al Qaeda-directed attack or an Al Qaeda-inspired attack," said Roger Cressey, a former official in the Clinton and George W. Bush administrations. ''In many respects it will be easier if it is an Al Qaeda-directed attack with a familiar command structure. If it is an inspired attack with no operational control over it, it is much more difficult to deal with. My gut tells me it was inspired."
Julianne Smith, at the Center for Strategic and International Studies in Washington, agreed. ''I would put my money on either British citizens or immigrants inside the UK, or a small group returning from the fighting in the Middle East," she said.
An unknown group calling itself the Secret Organization of Al Qaeda in Europe took responsibility on a website. The claim could not be verified; many specialists doubted its authenticity.
Nevertheless, new groups inspired by Al Qaeda that have been popping up on several continents represent a trend that had been predicted by the CIA's National Intelligence Council. ''Groups inspired by Al Qaeda, regionally based groups, and individuals labeled simply as jihadists -- united by a common hatred of moderate regimes and the West -- are likely to conduct terrorist attacks," the council said in a January report.
Whether the group claiming responsibility for the London attacks exists or not, what is clear is that the Iraq war and years of alienation have increasingly radicalized Europe's Muslims, especially in London, where at least two local terror cells have been broken up in the last year. London is also where Richard Reid, the British ''shoe bomber," studied with Zacarias Moussaoui, the French citizen who conspired with the 9/11 hijackers.
The British capital, described by some terrorism specialists as ''Londonistan," has a long history of pockets of Islamic militancy. The Washington-based Journal of Counterterrorism warned in a 1999 article about a ''web of terror," including militant fund-raising and propaganda groups operating out of radical mosques.
''Claiming to be persecuted political dissidents, these groups manipulate British asylum and speech law to create a shelter under which they may conduct their nefarious activities," Evan F. Kohlmann, a terrorism research specialist, wrote at the time. ''They have joined forces with coreligionists in Great Britain."
The new threat extends to the rest of Europe, experts said.
''Europe is a field of jihad, and it evolved from a logistical base for the operations of a centralized Al Qaeda to a battlefield itself," Simon said. ''The foot soldiers . . . recruited themselves right in their own slums. The alienation and the anger behind these attacks has been incubating in Europe for more than a decade. The war in Iraq has intensified the resentment, even fury, of these people."
Intelligence specialists worry that this new class of extremists provides a growing threat. ''People who are native grown or inspired are much harder to detect or infiltrate," said Michael Kraft, a former State Department official.
And America may not be immune. ''Radical Islam is spreading across Europe among descendants of Muslim immigrants," Robert S. Leiken, director of the immigration and national security program at the Nixon Center, writes in the current issue of Foreign Affairs. ''Disenfranchised and disillusioned by the failure of integration, some European Muslims have taken up jihad against the West. They are dangerous and committed -- and can enter the United States without a visa."
Brian Bender can be reached at firstname.lastname@example.org.