U.S. homeland security director Tom Ridge says the United States remains on an indefinite state of alert for more terrorist attacks. He adds that investigators have still not figured out who sent anthrax through the U.S. mail.
At a Wednesday news conference, Mr. Ridge said there is no change from the threat warning issued last week, that Americans must maintain a heightened sense of alert for more terrorist attacks. "I think this heightened sense of awareness, one of the challenges is to take the legitimate anxiety and fear that Americans still have, we will be on alert indefinitely," he said. "And when we have specific information from credible sources, we will appropriately give it to the law enforcement community."
Mr. Ridge said four post offices remain closed as a result of anthrax-contaminated letters sent through the U.S. mail. Four people have died from anthrax including two post office workers who investigators believe handled an anthrax-laced letter sent to a Senate office building.
Mr. Ridge said investigators have still not determined where the anthrax came from or who put it in the mail. "We haven't included or excluded either a domestic or an international source for the anthrax," he said. "There have been some suggestions that it could be domestic, but that has not been confirmed in any manner, shape or form."
Mr. Ridge said 25 people have been arrested in connection with anthrax hoaxes. So far, he says there have been more than 10,000 pranks involving false claims of anthrax contamination.