The office of the Council on American-Islamic Relations in Washington, D.C., was evacuated today after a "foreign substance" was received in the mail, officials said.
A field test was done on the white powdery substance found in the envelope along with a hate message mailed to CAIR's main office, according to Awad and Hopper.
Awad blamed recent terror events and Republican presidential frontrunner Donald Trump's rhetoric, arguing that "the number of recent threats have gone up significantly since Trump's comments, San Bernardino shooting and Paris attacks."
CAIR is the U.S.'s largest Muslim civil liberties and advocacy organization and is based in Washington, D.C.

ABC News' Sarah Shales contributed to this report.