At least one envelope or package ignited at a postal facility in Washington D.C. on Friday, a day after two packages ignited at government buildings in neighboring Maryland, Xinhua reported.
The envelope ignited at a postal facility in the northeastern part of the capital, which handles mails and packages sent to federal government agencies. The facility was set up in the wake of the Sept. 11, 2001 terrorist attacks.
The incident occurred after two o'clock Friday afternoon, when a cop was flagged down by a post office worker, D.C. Police Chief Cathy Lanier said at a press conference.
There was flash and smoke but no one was injured and the fire extinguished itself, Lanier said. The building was evacuated immediately.
D.C. police, the FBI, and the post inspector's office have all participated in the investigation, she said, the FBI joint counterterrorism task force will handle the evidence and send it to the FBI lab in Quantico, Virginia, for forensic analysis.
The envelop was addressed to U.S. Secretary of Homeland Security Janet Napolitano, CNN reported.
Another D.C. police spokesman said the envelop was similar to two packages that ignited at Maryland state government buildings Thursday.
One package was at the Jeffrey Building in Annapolis -- which houses agencies including the Governor's Office of Homeland Security, the Department of Veterans Affairs and the office of the Secretary of State -- and was addressed to state Governor Martin O 'Malley. The other was at the Maryland Department of Transportation headquarters in Hanover and was addressed to Transportation Secretary Beverley Swaim-Staley.
In both incidents Thursday, the book-sized packages gave off smoke and odor when they were opened by employees in the mail rooms of the two buildings. Employees who opened the packages just reported singed fingers. This was no serious physical harm, no property damage.
Police and FBI officials were still investigating causes of the incidents. The Maryland packages contained a note railing against highway signs urging motorists to report suspicious activity, investigators revealed.
The message read: "Report suspicious activity! Total Bullshit! You have created a self fulfilling prophecy."