Anthrax found at White House mail facility.

Byline: Naftali Bendavid and Jeff Zeleny

WASHINGTON _ Anthrax has been detected on a machine that opens letters bound for the White House, officials announced Tuesday, bringing the bio-terrorism scare closer to another symbol of American power.

No one at the White House has tested positive for exposure to the bacteria, presidential spokesman Ari Fleischer said. The anthrax was found on the blade of a letter-slitting machine at a White House mail-handling facility on a military base a few miles from 1600 Pennsylvania Avenue. Officials do not believe the deadly spores were transmitted to the executive mansion itself.

"We're making sure the West Wing and the White House is safe," President Bush said. "I'm confident that when I come to work tomorrow, that I'll be safe."

The incident delivered another jolt to the nation's leaders as they grappled with the most extreme case of bioterrorism in the nation's history. Officials also confirmed that two Washington postal workers died this week of anthrax inhalation, as was suspected, and they announced that a postal worker in New Jersey is believed to have the severe respiratory form of the disease, the first time inhalation anthrax has been confirmed there.

In Washington, federal authorities defended themselves against accusations that they were ill-prepared and slow in responding to the anthrax outbreak. Some postal workers wondered aloud why officials took to long to test employees at…