Government officials suspect the terrorists, recruited in Europe, have been dispatched to plan attacks against Europe and possibly the United States. The alleged terrorists hail from Britain, the Netherlands, Denmark, Germany, Romania and Estonia, sources said.
Intelligence officials claim the remote tribal areas along the border between Pakistan and Afghanistan have in the last several years become a haven for terrorist recruiting and training. Hundreds of radicals from across the region have flocked to al-Qaeda training camps in the area.
In interviews with ABC News and in a series of little-noticed public statements and reports, intelligence officials have said they believe al-Qaeda has successfully completed a major goal: recruiting and training Western would-be terrorists.
"Al-Qaeda is improving the last key aspect of its ability to attack the US: The identification, training and positioning of operatives for an attack in the Homeland," according to a February Threat Assessment report from the Director of National Intelligence.
"We have seen an influx of new Western recruits into the tribal area since mid-2006," the report said. Those Western recruits are thought to be more difficult to detect and able to easily enter Europe and the US and blend in with Western culture.
'Mass casualties in US'
"They're recruiting operatives from Europe. Why? If you're from Europe, it doesn't require a visa to fly to the United States," Mike McConnell, the director of National Intelligence, said in a speech in March. "So if you can get a disgruntled person in Europe to come to Pakistan to be trained in how to buy something commercially – hydrogen peroxide – and use it in a particular way, you could have mass casualties in the United States greater than 9/11," he said.
Despite these public warnings, members of Congress say they are frustrated that the Bush administration and Pakistan have not done more to shut down the camps. "The result that we have today is not acceptable," said Rep. Pete Hoekstra. "You can't have those camps in place in Pakistan."
Intelligence officials tell ABC News that the administration is trying to target key al-Qaeda leaders in the tribal regions with Predator airplane attacks and recently killed one leader who helped coordinate European operatives.
The US has also urged the Pakistani government to be aggressive in pursuing terrorist leaders in the tribal areas, these sources said. The Pakistani government has said it is committed to stopping militants in the area.