U.S. National Counterterrorism Center spokesperson Maura Beard said that officials there have not yet reached a conclusion that there is a connection to foreign terrorism with the suspicious package.
NCTC says the FBI has the lead for the investigation and added that they will continue to collaborate with all law enforcement agencies, CNN reported.
The Secret Service said earlier that "potential explosive devices" were mailed to the homes of former State Secretary Hillary Clinton, former president Barack Obama and former CIA Director John Brennan.
