A Muslim support group cleared its national headquarters on Capitol Hill on Thursday after getting a letter containing white powder, but staff was later permitted to   re-enter after authorities led preliminary tests and deemed the substance safe. The letter got by the Council on American-Islamic Relations (CAIR) additionally contained a note that read, "Die a painful death, Muslims," according to CAIR staff lawyer Maha Sayed.

In California, a CAIR branch office in the Bay Area city of Santa Clara was likewise evacuated on Thursday after accepting an envelope with an unknown powder inside. Further information was not available on the grounds that local authorities couldn't promptly be reached.

Law enforcement authorities and Muslim groups around the United States have braced for a rise in anti-Muslim conclusion after two Muslims shot dead 14 individuals in California a week ago. The Federal Bureau of Investigation is examining the shooting as a demonstration of terrorism.

The presence of white powder in the letter sent to CAIR was reminiscent of the 2001 anthrax attacks that murdered five individuals and sickened 17. The FBI has taken ownership of the letter, and will test it further, as indicated by FBI representative Andrew Ames.

Around three CAIR representatives came into contact with the powder and were isolated in the building while police and firefighters investigated the scene, said group representative Hooper, including that the rest of the office staff held up outside on the sidewalk.

CAIR staff lawyer Sayed said on the group's Facebook page that the association gets hate messages day by day. It's alarming to encounter the hate manifest itself to such a genuine level. This won't stop us from keeping on securing the civil rights and freedoms of all Americans, Sayed included.

The occurrence happened days after Republican presidential leader Donald Trump proposed briefly banning Muslims from entering the United States, sparking outrage in the country and around the world.