FBI - No anthrax link yet to Sept. 11 attacks

WASHINGTON -- The FBI has investigated 2,500 reports of possible anthrax exposure but has found no links yet between them and the Sept. 11 hijackings, bureau Director Robert Mueller said Wednesday.

Telling the nation's mayors of the challenge facing his investigators, Mueller said the FBI is responding to every report of an anthrax attack even though the vast majority are hoaxes or false alarms.

The largest investigation in FBI history now involves more than 7,000 bureau personnel -- about one in four employees -- looking into the hijackings and the subsequent anthrax attacks. Much is still to be learned about the bioterrorism assaults, which have produced a growing number of anthrax cases.

"At this point, it is not clear if the few confirmed anthrax exposures were motivated by organized terrorism," Mueller said in a speech to the U.S. Conference of Mayors. "But these attacks were clearly meant to terrorize a country already on the edge. We're responding swiftly to each and every incident."

Beyond the anthrax investigation, federal authorities were contending with the death of a Pakistani man who had been in custody on immigration violations.

Guards found Muhammed But, 55, of Queens, N.Y., dead at 10:45 a.m. Tuesday at the Hudson County, N.J. Jail. An autopsy determined the man died of natural causes from a heart problem, said Emily Hornaday, a state Division of Criminal Justice spokeswoman.

Doctors tested the man for anthrax, using nasal swabs and blood and tissue samples, said Dr. Lionel Anicette, the jail's medical director. All the tests were negative.

But was arrested Sept. 19 as part of the investigation into the terrorist attacks, a government source, speaking only on condition of anonymity, told The Associated Press on Wednesday.

Mueller said the FBI is "pouring its heart and its soul" into the investigation. Agents have gotten on their hands and knees at crash sites and are laboring over more than 3,700 pieces of evidence, he said.

Despite the enormous resources being devoted to the investigation, the FBI's priority is preventing another attack. Mueller repeated the Bush administration's consistent warnings that a high probability exists for more assaults.

He acknowledged the bureau has done better in the past at tracking down terrorists than stopping them.

"Now, it may well be overly optimistic to think that every single attack can be prevented. But we can certainly give it everything we have got, and that is exactly what we are doing," Mueller said.

The FBI has now entered its hijackers "watch list" into computer records available to state and local law enforcement agencies, he said. The list includes individuals the FBI wants to speak with, or those believed to have helpful information.