The Council on American-Islamic Relations' office was evacuated Thursday after a "foreign substance" was found in the mail with a "hate message," a CAIR spokesman told TPM.
"There was a hate message. We cannot specify what it said. The FBI has asked us not to," the spokesman said.
An initial test of the substance was found to be negative, according to a report from BuzzFeed News and the roughly two dozen people evacuated at the Capitol Hill office have returned to the building.