Tranh Cong Phan, 43, has been arrested in connection with sending multiple suspicious packages to government addresses. The packages were sent to locations in the Eastern Seaboard, according to the FBI. Most of them went to places in Washington D.C. and the surrounding area. Phan, a Seattle, Washington area resident, was arrested at his home less than 24 hours after the packages were discovered, according to Vox.

Officials believe 12 packages were sent in total to government and military addresses. Defense Secretary Jim Mattis said on Tuesday that all parcels sent to Defense Department facilities are now under the restriction of federal authorities. "Basically there's a set procedure, they went through the procedure," Mattis said. "We've had nobody injured and all those packages and all the evidence is accessible and is the hands of the FBI right now."

Phan's motive has yet to be been confirmed by officials.

The packages arrived at the Joint Base Anacostia-Bolling in Washington, DC; the CIA in Langley, Virginia; Fort Belvoir in Virginia, where the National Geospatial-Intelligence Agency is headquartered; the National Defense University at Fort McNair; and the Naval Surface Warfare Station in Dahlgren, Virginia. The parcels reportedly "contained potential destructive devices" according to the FBI per NBC News. FBI investigators also say that the packages looked like they originated from the same person. Letters were included in some of the packages and were described as rambling and disturbed by an official.