Two letters addressed to Defense Secretary James Mattis and another military official tested positive for the toxin ricin at a Pentagon mail sorting facility, the U.S. Defense Department said Tuesday.
In a statement, the Federal Bureau of Investigation said: "Special agents took possession of two suspicious envelopes that had been screened at the Pentagon mail facility".
The FBI issued a statement saying it has taken possession of two suspicious envelopes screened at the Pentagon mail facility and they are undergoing more testing.
The packages never made their way into the Pentagon, but were flagged in a mail delivery building next door on Monday, the spokesman said.
The remote mail facility was set up after the 9/11 terrorist attacks and the subsequent anthrax scare, to ensure that letters and packages can be screened for unsafe substances before they enter the Pentagon.
An official said one of the envelops was mailed from inside the United States; it's not clear where the other one came from.
It can be used in powder, pellet, mist or acid form.
On Tuesday, a hazmat team was sent to the campaign office of Senator Ted Cruz in Houston to investigate a "powdery white substance", according to the Weekly Standard. If the beans are chewed and swallowed, the released ricin can cause injury.
Sources tellCBN News the mail initially tested positive for ricin.