FBI investigators responded to multiple military locations in the Washington, D.C. area on Monday after several suspicious packages were spotted

One package was delivered to Fort McNair’s National Defense University around 8:30 a.m., at which point the building was evacuated and an Army Explosive Ordnance Disposal (EOD) team came in from nearby Fort Belvoir, Virginia, to evaluate the situation.

Army spokesman Michael L. Howard confirmed that the package was found to be safe. “At 12:10 p.m., 52nd Army Explosive Ordnance Disposal from Fort Belvoir, VA, confirmed the package tested positive for black powder and residue. The X-ray conducted indicates suspected GPS and an expedient fuse were attached. The package was rendered safe. No injuries are reported.”

At 11 a.m., Dahlgren Naval Air Station reported a similar suspicious package.

Just hours later, additional reports rolled in detailing a number of other suspicious packages, all found at military or government installations. Two arrived at different locations at Fort Belvoir on Monday afternoon, while others were found at Joint Base Anacostia-Bolling and White House and CIA mail facilities.

Although all of the individual packages were eventually rendered “safe,” reports indicated that they all contained explosive components. One contained a circuit board and a vial filled with an unidentified liquid. Several of the packages were reported to have contained letters, which one official described to NBC as “disturbing.”

According to Fox News, the FBI has taken possession of all of the packages and has moved them to the Quantico field office to continue the investigation.