and are downplaying this to prevent major widespread panic.
In another incident, a white powder bomb was activated in a bank in Florida on Thursday, spokesman Richard Boucher said during a news briefing. Several customers became ill and were rushed to the hospital then released. He said the FBI and CDC hazardous materials squads had been called. Another State Department official said the area had been secured and an evacuation had been performed.
In New York, Mayor Rudy Giuliani announced at a joint news conference with NBC executives that The New York Times also had received a suspicious envelope, and that investigators were testing its powdery contents.
Barry Mawn, head of the New York office of the FBI, said investigators had no evidence the anthrax infection was related to the September 11 terrorist attacks against the World Trade Center towers.
"We see no connection whatsoever to 9-11. The way we will handle this is to open it as a separate matter and proceed from there," he said.
The NBC employee, a woman, is in good condition and expected to recover, NBC executives said. Giuliani said she had a low-grade fever and a bad rash.
The woman, who was not identified beyond her affiliation with "Nightly News" anchored by Tom Brokaw, received an envelope September 25 containing a white powder that tested negative for anthrax. She later tested positive -- the results just became known Friday -- but has been taking antibiotics since October 1.
"She is in good health and good care," Lack told a news conference.
Giuliani said, "We don't have any additional numbers of people reporting symptoms. The chances that this is contained are very good."
The employee was put on an antibiotic regimen as a prophylaxis on October 1, Giuliani said. The positive results became known Friday morning.
"All employees who may have been exposed will be tested," Giuliani said. "And some of those people will be given antibiotics."
Investigators will conduct environmental tests on several areas of the NBC building, he said.
Giuliani said the city was reacting to the incident with "an excess of caution." "Everybody wants to go to the extra lengths to make sure there are no problems," he said.
Police closed 43rd Street between Eighth Avenue and Broadway -- in the heart of the usually congested theater district where the Times building is located -- to vehicle and pedestrian traffic.
NBC's Wright said the employee received a letter with a suspicious powder and reported it to authorities. The powder, he said, tested negative for anthrax.
The Centers for Disease Control and Prevention, the FBI, and the New York City Health Department are investigating.
In Washington, an administration official told CNN that President Bush was informed of the latest anthrax case before leaving for an appearance at a March of Dimes event.
A government source told CNN the source of the bacteria was "undetermined" and that state and local public health officials have been in contact with federal health and law enforcement authorities.
Cutaneous anthrax is not as serious as inhalation anthrax, which brings bacteria spores directly into the lungs.
Executives said NBC had tightened security and was in the process of setting up an information center for employees. ABC and CBS officials told CNN they had received no anthrax threats. However, CBS has closed off its mailroom at its New York headquarters, according to CBS spokeswoman Sandy Genelius, who added, "We are no longer taking in any new mail."