An anthrax scare Tuesday at Montgomery's municipal court building is not related to a string of suspicious letters sent to Alabama congressional offices around the state, the FBI said.
Investigators made the determination as yet another letter containing white powder was found Tuesday at U.S. Sen. Richard Shelby's office in Mobile.
FBI spokeswoman Angela Tobon said that while the Montgomery letter was not connected to the nine found Sunday and Monday at congressional offices, the one found at Shelby's Mobile office was linked to them.
In Montgomery, workers were evacuated and a hazardous material team was brought in after white powder was found in a letter. Montgomery's fire department said the material turned out to be baking soda, and the court building reopened Tuesday afternoon.
The powder found in the nine earlier letters turned out to be a common household sweetener.
Mayor Todd Strange said the letter sent to the Montgomery court building came from out of state, while the FBI said the nine letters that previously showed up at congressional offices in five cities were mailed from inside Alabama.
"It came from an individual purporting to be paying their traffic ticket to the municipal court," Strange said. "When the employee opened the envelope this white substance fell out of it."
Six employees were exposed to the letter, but no injuries were reported.
All the previous letters were mailed to Republican members of Alabama's congressional delegation and found Sunday or Monday in Mobile, Foley, Montgomery, Birmingham and Anniston.
Authorities said they suspected the same person sent those letters, at least one of which bore a Montgomery postmark. At least some of the letters were mailed last Thursday and weren't opened or delivered until after the New Year's holiday.