Last Updated Mar 27, 2018 8:06 AM EDT
WASHINGTON -- Authorities have arrested a man suspected of sending ato military bases and government sites in the Washington, D.C. area, the FBI announced Tuesday. It said the packages contained "potential destructive devices" and cautioned that similar packages could have been mailed in the area that have not yet been found.
The FBI identified the suspect as 43-year-old Thanh Cong Phan. He was arrested Monday at his residence in Everett, Washington. Phan was scheduled to appear in court at 2 p.m. on Tuesday.
CBS News national security correspondent David Martin reported that the arrest was made about 12 hours after the packages were discovered. Court documents are expected to give insight into how many packages were mailed and whether or not the devices were actually explosive.
A law enforcement source says there does not appear to be any connection to terrorism, CBS News' Pat Milton reports. The packages were mailed by the U.S. Postal Service from the state of Washington to about 10 federal facilities in D.C. area, including the CIA. All of the contents of the packages were similar.
Phan's motive remains unclear at this time.
Multiple suspicious packages were left at Fort Belvoir, Fort McNair, Joint Base Anacostia-Bolling and the Naval Surface Warfare Center in Dahlgren, Virginia. The packages were each rendered "inert" by the facility's disposal units, although that does not mean that they were explosive. The packages sent to Joint Base Anacostia-Bolling and the Naval Surface Warfare Center are not believed to have contained any explosives.
The FBI is now in possession of the packages and is trying to determine if they were explosive and who sent them. The package sent to McNair, an Army base in Washington, D.C., tested positive for black powder and had a fuse attached.
"The FBI responded to multiple government facilities today for the reports of suspicious packages," the bureau said in a statement. "Each package was collected for further analysis by the FBI."
All government facilities have been screening everything coming into federal facility mailrooms, a source told CBS News. During screening, the packages were found to be suspicious, although it is unclear what made them suspicious.
It is also unclear whether each facility randomly found suspicious packages or whether an alert was sent out after one was found to be suspicious. The investigation is ongoing.