FBI: Pre-Super Bowl white powder deemed not hazardous

NEW YORK (CNN) -- The FBI said Friday that white powder found at New Jersey hotels near the site of the Super Bowl and at the Manhattan office of former Mayor Rudy Giuliani proved to be non-hazardous.

Hazardous materials teams and bomb squads responded after white powder was found at several hotels near New Jersey's MetLife Stadium, authorities said.

The FBI In New York tweeted Friday afternoon: "Substances in suspicious letters in New York and New Jersey deemed non hazardous. Additional testing to come."

The contents of one letter sent to the Homewood Suites in East Rutherford was tested and determined to be cornstarch, East Rutherford Mayor James Cassella told CNN.

And a New York police spokesman said the letter sent to Giuliani's office contained a "non-toxic substance." Still, eight employees in the mailroom were decontaminated as a precaution, and no one has shown any sign of illness.

The contents of the letter "did not appear threatening," a New York police spokesman said, adding that the letter included the line, "always in my thoughts."

The letter was postmarked from Toronto, Ontario, and contained a name and return address. New York law enforcement authorities were in touch with Canadian authorities to pursue the source of the letter, police said.