The FBI Portland office says six letters purporting to deliver threats and a powdery substance have arrived at buildings across Portland over the past two weeks, with more letters possibly being in the post.
It said in each and every case, testing has shown that the substance included in the envelopes is non-toxic.
“While more letters may arrive over the next few days, the FBI and its local partners believe they have stopped the sender or senders’ ability to continue this stream of threats.
“Additionally, the FBI would like to reassure the public that there is no known risk to public safety,” the agency said in a statement.
The person or people responsible for sending these letters potentially face severe penalties for their actions, including up to 10 years for sending a threatening communication through the mail and up to five years for a hoax device.
No charges have been filed at this time and due to the on-going nature of the investigation, no further information would be released.
The FBI was working with the Portland Police Bureau and the Portland Fire Bureau on the investigation.
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