"Since Monday, letters containing a note and suspicious white powder have been received by the offices of more than 30 governors' offices across the country," the statement reads. "The white powder in each of these letters has been field screened and the tests have met with negative results. The powder has been forwarded to local laboratories for further testing. The FBI has contacted the governors' offices to be on the lookout for additional letters."
The FBI warns that "these letters are all similar in nature," all are postmarked from Texas and "it's likely there will be more."