WASHINGTON -- Security officials sealed off one wing of an eight-story Senate building and dispensed precautionary antibiotics by the hundreds on Tuesday as the FBI probed similarities between an anthrax case in New York and a spore-spiked letter mailed to Majority Leader Tom Daschle.
"Obviously, these are difficult times," said Daschle, as the Senate -- and the nation it represents -- grappled with the unsettling threat of bioterrorism.
A thousand miles to the south, Floridian Ernesto Blanco lay ill in a hospital with the inhalation form of anthrax, less than two weeks after a co-worker died of the same illness.
In New York, headquarters for many of the nation's high-profile news media corporations, officials said they expected full recoveries for two people infected with a less lethal form of the disease. They included an NBC news employee and the 7-month-old son of an ABC producer.
Yet five weeks after terrorist strikes killed 5,000 in New York and Washington, the nation reeled under a continuing series of disclosures involving letters tainted by anthrax bacteria, spores discovered in a postal facility in Florida, countless innocent scares, and a not a few malicious hoaxes.
"As the evidence unwinds, there may end up being a formal tie" between the anthrax cases and Osama bin Laden's terrorist network, said Tom Ridge, recently sworn in as the head of the new Office of Homeland Security.
FBI Director Robert Mueller told reporters there were "certain similarities" between the letter addressed to NBC anchor Tom Brokaw and the mail unsealed in Daschle's office across the street from the Capitol several days later.
The Justice Department released photos of the two envelopes, addressed in handwritten block letters that appear similar. Both contained a postmark from Trenton, N.J, and both also appeared to have metered stamps.
The Brokaw envelope is postmarked Sept. 16 with no return address. The Daschle letter is postmarked Oct. 8, and the return address is "4th Grade, Greendale School, Franklin Park, NJ 08852." Justice Department officials said there is no such school.
Officials said they released the photos in hopes the public could aid in their investigation.
"We were told that it was a very strong form of anthrax, a very potent form of anthrax that clearly was produced by somebody who knew what he or she was doing," Daschle told reporters after a briefing by FBI and other officials.
Investigators dispatched to a New Jersey mail processing facility scanned surveillance tapes and canvassed postal workers as they sought clues about the origin of the two pieces of mail. But officials said the letters could have started at any of 46 smaller facilities before arriving at the main post office.
In steps that underscored the extraordinary level of concern, Capitol police cordoned off an entire wing of the eight-story Senate office building around the majority leader's office so they could check for evidence of contamination. Officials said the area that was sealed was serviced by one of five or six separate ventilation systems in the building.
A dozen senators' offices were temporarily relocated for the tests, expected to last two or three more days, and mail shut down for the second straight day throughout the Capitol complex.
Officials invited aides, tourists, reporters and anyone else who might have been in the area Monday to report for nasal-swab tests. Anyone who did was given a three-day supply of antibiotics and told to report back Thursday to obtain the lab results.
"We have to throw out the net as widely as possible," said Dr. John Eisold, the Capitol's attending physician. "If we screen them, we treat them."