The FBI says more than two dozen suspicious letters containing a white powder were mailed to District schools, forcing several evacuations, lock-downs, medical evaluations, and more than a few anxious parents.
The FBI isn't saying where the letters came from, although investigators have confirmed they originated from outside the District. WRC-TV obtained an image of one of the letters showing a postmark fro Dallas, Texas. The letters also included references to al-Qaida, WRC-TV reports.
The FBI also says similar letters have been delivered to schools elsewhere in the U.S. over the past few weeks.
While authorities say the white powdery substance is harmless, the letters created a hectic and -- as D.C. Police Chief Cathy Lanier put it -- intense day for authorities as they raced from school to school as more letters were uncovered.
No injuries or illnesses were reported at any of the schools. Medical evaluations were performed on about a dozen school employees who work in mail rooms.
Mayor Vincent Gray called letters a dastardly act and says the FBI is leading the investigation.
View more videos at: http://nbcwashington.com.