All is clear at the Council on American-Islamic Relations’ national building on Capitol Hill after an employee found a suspicious substance Thursday.
D.C. police evacuated the office and cordoned off the street after an employee opened an envelope and discovered a white powder.
A hazmat team field-tested the substance and found it wasn't dangerous.
Employees were allowed back in about 3 p.m.
"We receive hate messages daily because of our advocacy on behalf of the American Muslim community," CAIR staff attorney Maha Sayed said in a post on Facebook. "It's frightening to experience the hate manifest itself to such a real level. This will not deter us from continuing to protect the civil rights and liberties of all Americans."
The FBI also went to the scene, NBC News correspondent Pete Williams reported.