(AP) - Gov. Tim Pawlenty's spokesman says a staffer in the governor's office opened a letter containing an unknown white powder on Monday afternoon.
Governors in at least six other states received similar letters on Monday, but tests indicated the powder in five wasn't harmful.
Spokesman Brian McClung says Capitol security and the State Patrol are working with the FBI to investigate the letter and the powder has been sent to the state health lab for tests.
McClung says the letter had a Dallas, Texas, postmark.
He says the letter was opened in an area where only one staffer was working, and the worker followed protocol by contacting Capitol security and keeping the letter where it was opened.
FBI spokesman Rich Kolko said Tuesday the Dallas FBI office is investigating who sent the letters to the governors' offices in Minnesota, Alabama, Michigan, Mississippi, Missouri, Montana and Rhode Island.
He says governors' offices in all other states have been warned to be on the lookout for suspicious letters.
The FBI says even though the letters are a hoax, sending them was a crime because law enforcement and public safety personnel were called away from other duties to respond.
(Copyright 2008 by The Associated Press. All Rights Reserved.)