The FBI is investigating 11 suspicious letters containing a white powder that were sent to various New Jersey government offices this month.
The letters have been received at police departments and government offices throughout northern New Jersey. The first one came July 17.
Letters have been received in Totowa, Clifton, Wayne, Ringwood, Fair Lawn and Woodland Park.
All the letters are being tested. The FBI says first three letters tested came back negative for biological agents and no injuries have been reported.
Letters containing white anthrax powder killed five people in the fall of 2001. Some were processed at a postal facility in Hamilton, just outside Trenton. Two workers there contracted the skin form of anthrax, but both recovered.