But the search for suspicious letters quickly expanded beyond the Florida post offices.

For all settings, law enforcement authorities determine the credibility of suspicious letters, packages, and other potential threats.

Smoking nervously, She said a suspicious letter had been found this morning in a sorting area.

Bacon wrote her daughter a very suspicious letter.

A third suspicious letter was in an unknown tongue and even an unknown alphabet.

Even so, a backlog has developed, with people sometimes waiting several days to learn whether their suspicious letters contained anthrax.

"They have traced the path of the suspicious letter and identified all who may have come in contact with it."

One, he said in an interview, amplifies procedures already in place for dealing with suspicious letters and packages.

Advises that if you receive a suspicious letter or package: Stop.

Police agents were called to open more than 50 suspicious letters in Vienna today, but no bombs were found.