Officials said 6,000 postal workers in the Washington/Baltimore area and 7,000 in New York and New Jersey were taking antibiotics because anthrax spores were found at various postal facilities.
At the State Department in Washington, officials told United Press International initial tests on a mail pouch destined for Lima, Peru, came back positive for anthrax.
"There is at least one mail pouch where they may have found something," a senior State Department official told UPI. This source described it as a "potential positive."
But another State Department official told UPI, "It looks like anthrax. They are getting definitive results right now."
The State Department on Friday sealed off all of its overseas and domestic mail facilities after a dockworker at its Northern Virginia mail depot was diagnosed with inhalation anthrax infection. Hazardous-material workers checked the department's ventilation system and officials said Monday nothing was found.
State, like most government agencies, gets its mail through the Brentwood sorting facility near Capitol Hill, which handled the one anthrax-laced letter confirmed in Washington.
Secretary of Health and Human Services Tommy Thompson said Monday new traces of anthrax also have been discovered at an HHS building. White House spokesman Ari Fleischer said he believed the anthrax was found in the building's mailroom.
Questions sharpened over the weekend on whether the bacteria might have come from an overseas government source -- possibly Iraq, which is known to have done anthrax-weapons research. Questions focused on whether the mineral compound bentonite might have been added to the anthrax to help the spores linger in the air.
Maj. Gen. John Parker, the top Army scientist on the anthrax investigation, said Monday investigators did find silica, a clay substance, mixed in with anthrax contained in the letters sent to Senate Majority Leader Tom Daschle's office and the New York Post newspaper. Parker said they had not found aluminum, a component in bentonite, a substance supposedly used by the Iraqis. Parker said he did not know, however, what the silica finding means.
Meanwhile, the Supreme Court on Monday heard argument about six blocks away from its usual home on Capitol Hill, the first time since the British burned Washington in 1814 that the justices have been driven from their courtroom by a threat. Anthrax spores were confirmed Monday in the mailroom of the Supreme Court building. Anthrax also was found last week in the court's mail screening warehouse in the Maryland suburbs.
At least some of the justices were taking an antibiotic regimen as a precaution, though court officials refuse to confirm.
The Department of Justice closed its Landover, Md., mail facility over the weekend after it tested positive for anthrax spores. The facility, which also receives its mail from Brentwood, handles mail for Justice and some of its related agencies.
"Areas which specifically handle mail for the main Justice building, including the Attorney General's office and other leadership offices, were among those that tested positive," a DOJ statement said.
Centers for Disease Control and Prevention anthrax expert Dr. Bradley Perkins in Atlanta said Monday the agency is now working under a hypothesis that other letters -- yet undetected or opened -- in the Washington mail system may be carrying anthrax as well. He said some 50 scientists at CDC were working around the clock analyzing the anthrax samples being sent in.
The anthrax trails from New Jersey, Washington and New York appear to have links. Investigators have said three anthrax letters, sent to NBC News in New York, Daschle, D-S.D., and the Post earlier this month may be linked via similar handwriting on their envelopes. The strain of anthrax used in all of the letters is the same -- a naturally occurring anthrax that is susceptible to antibiotics. All three letters were sent through Trenton, N.J.
Standard mail processing of the Daschle letter, at Brentwood -- via mail sorting machinery -- appears to have spread the anthrax spores to other mail then sent to other government agency mailrooms and possibly to private businesses.
Perkins said in cases where it is possible, the U.S. Postal Service has recalled mail that may have contained a contaminated letter or package.
"That mail is being recalled and intensively evaluated by FBI," Perkins said.
In Florida, the anthrax investigation is different. Officials have not found any anthrax-laced letters as yet -- however, the mailroom at American Media Inc. in Boca Raton, where the anthrax scare began, has tested positive for anthrax. Several area post offices have tested positive as well.
Florida officials said suspected anthrax found by postal workers in an envelope addressed to Rep. Mark Foley, R-Fla., has tested negative. The envelope leaking white powder was found at the Palm Beach Gardens, Fla., post office north of Boca Raton.
Elsewhere, Boston's General Mail Facility, in terms of square footage the second-largest mail processing center in the country, was tested for anthrax Sunday, but preliminary results show no traces. The firm conducting tests of some 200 mail facilities across the nation "found no preliminary findings of anything hazardous, which is what we expected and hoped for," said Boston postal spokesman Robert Cannon.
Despite the fact no cases of anthrax have been confirmed in Boston, postal employees are nervous, according to 35-year veteran postal worker Joseph Murray.
"I'm glad they've done something to check now rather than waiting for something to happen down the road," he told the Boston Globe.
In Fort Worth, Texas, U.S. Postal Inspector Kenny Smith said gloves and masks have been made available to all postal employees in the region but their use is voluntary.
"From what I've seen they are concerned, but for the most part they are handling it very well," he said. "I believe they see the threat as relatively low around here, but obviously they are concerned."
Smith said he would estimate "well less than half the employees" he has seen are wearing the masks and gloves.
There have been lots of false alarms in the area, which includes North Texas, Oklahoma and Arkansas, and a few hoaxes but to this point no actual cases of anthrax contamination or exposure in the region, he said.
Also, some postal workers were considering legal action in the wake of the anthrax mail assaults.
Wayne Cohen, a personal injury lawyer with the Washington-based firm Cohen & Cohen, told UPI he has been approached by four postal employees, two with suspicious symptoms and two with confirmed cases of inhalation anthrax.
"We are looking at what may be viable claims against the government and entities with which the government contracts if it is shown that testing wasn't done in a timely and appropriate fashion," said Cohen, who also is a law professor at George Washington University.
Legal scenarios could include making so-called non-fault based claims under workers' compensation. In such cases, plaintiffs are only required to show they suffered an injury not that the injury was based on egregious conduct by employers. Such cases are relatively straightforward and often do not require attorneys.
But private claims against the government or contracting parties would require the parties to prove egregious conduct.
Cohen said U.S. law makes it possible to seek claims against known terrorists states in cases where the terrorists' assets are frozen.
"If a terrorist state was behind the anthrax, then anyone who suffered may have a claim against the terrorists," said Cohen. "But everything I've read until now suggests no direct ties to bin Laden or his network."
The CDC said Monday the number of anthrax inhalation infections remains at 13, eight inhalation and five cutaneous. Two Washington postal workers and American Media Inc. photo editor Bob Stevens, of Lantana, Fla., have died from inhalation anthrax infection. A co-worker of Stevens also was diagnosed with inhalation anthrax but is recovering at home. Two other D.C. postal workers, the State Department worker and a postal worker from the New Jersey Hamilton Township post office also are hospitalized with this more serious type of anthrax.
(With additional reporting by Kelly Hearn, Mike Kirkland, Eli Lake and Nick Horrock in Washington, Phil Magers in Dallas, Dave Haskell in Boston and Les Kjos in Miami.)