U.S. intelligence has detected Al Qaeda operatives communicating with one another in Pakistan with an eye toward regrouping for terrorist attacks against Western interests in Afghanistan and elsewhere, an American official said Wednesday.

These operatives, and some Taliban allies, are operating in small groups on the Pakistani side of the Pakistan-Afghan border, much like the "pockets" the U.S. is attacking the Gardez area, just across the border in Afghanistan.

They probably number in the hundreds, the official said, speaking on condition of anonymity. Many fled the U.S. bombing but are showing signs of planning to regroup.

It's unclear who might be leading the effort, the official said. A number of senior Al Qaeda and Taliban leaders, including Usama bin Laden and Mullah Omar, remain at large.

The New York Times, citing unidentified government officials, reported on Wednesday that hints of Al Qaeda's regrouping in Pakistan came from intercepted e-mails and other Internet traffic.

Attorney General John Ashcroft declined to discuss the e-mails during a news conference on Wednesday.

"I can just say that we use every tool and weapon in our arsenal to disrupt them and to learn about and prevent terrorist attacks and the activities of our enemies," he said.

Other officials were hesitant to divulge information about the sources of U.S. intelligence, fearing it could cause the Al Qaeda to change their methods of communication.

"Every time we adopt or adapt some new ploy to identify them ... they attempt, as one would expect, to adapt their procedures," FBI Director Robert S. Mueller said last week.

Several Web sites purporting to have links to Al Qaeda have surfaced in recent months, although they are usually quickly taken down by providers. It is unclear if operatives could use these sites to communicate.

Worldwide, U.S. officials have been working feverishly to get a fix on Al Qaeda's surviving members and leaders since the war in Afghanistan. Many rank-and-file from the group have scattered, with some returning to their home countries throughout the Islamic world.

The activity in Pakistan doesn't yet appear to be a complete coalescing of the group, officials said.

Cells remain active in the United States as well, Mueller said Wednesday before the House Appropriations subcommittee responsible for the Justice Department's budget.

"We believe that we are still targeted, that there are Al Qaeda associates or individuals around the world and some in the United States that are intent on committing terrorist acts within the country," he said.

The United States has also detected signs of a resurgence by the Al Qaeda and their allies inside Afghanistan.

Intelligence officials have also learned of plots to conduct multiple car bombings against Western interests and the interim government in Kabul headed by Hamid Karzai, one official said.

In addition, officials have detected activity at Al Qaeda training camps bombed earlier in the war, including several in the Gardez area.