New York City officials are reassuring area residents after an employee of NBC News in New York tested positive for anthrax.

City officials say the NBC employee initially tested negative for anthrax in late September when she opened a letter containing a powdery substance. But she continued to show the flu-like symptoms of the infection and a subsequent biopsy showed the employee had contracted cutaneous anthrax. This means she contracted the infection through the skin. Last week a photo editor at a media company in Florida died from respiratory anthrax and, subsequently, a mail room employee at the same Florida company tested positive.

NBC officials say the employee in New York is being treated with antibiotics and is in good health.

New York City Mayor Rudolph Giuliani says the city is responding with "an excess of caution." All employees who may have been exposed will be tested by local health officials and the federal Center for Disease Control. But the Mayor cautioned residents to stay calm, reminding them that anthrax is not contagious. "People should not overreact to this. They should realize that all of the events that have occurred, particularly September 11 and things after that, when we have situations like this everybody wants to go the extra length, particularly all the health agencies, to make sure that there are no problems," he said.

Police officials and the FBI are investigating the incident, but local FBI chief Barry Mawn says the incident does not appear to be related to the September 11 terrorist attack on New York's World Trade Center. He says the FBI is investigating hundreds of anthrax hoaxes across the United States. "We see no connection whatsoever to September 11. The way we would handle this is to open it as a separate criminal matter and proceed from there," he said.

The letter was received at NBC's Rockefeller Center offices in the densely populated midtown section of New York City.