WASHINGTON (AP) - A building housing the Washington bureau of ABC News was evacuated Thursday because of a suspicious envelope containing a white powdery substance, District of Columbia authorities said.

D.C. Fire and EMS spokesman Alan Etter said there was no note or address on the small envelope. No one has reported any medical symptoms, he said.

Firefighters and police were on the scene trying to determine whether the packet poses a threat, and the downtown building was evacuated as a precaution, Etter said.