Pipe bombs and other suspicious packages targeting former Secretary of State Hillary Clinton, former President Barack Obama, CNN and key congressional leaders were intercepted in a rash of attacks Wednesday.
A similar device was found Monday at the New York home of liberal, billionaire George Soros, a major contributor to Democratic causes.
There were no explosions and no reports of injuries.
The Secret Service intercepted a suspicious package addressed to Obama early Wednesday morning, just hours after the package addressed to Clinton was intercepted at a mail facility in Westchester County, New York.
The Secret Service says its personnel intercepted the package addressed to the Obamas' Washington, D.C. home.
"What we saw here today was an act of terrorism. Attempting to undermine our free press. We will not tolerate this," said Mayor of New York, Bill de Blasio.
Officials said the packages were immediately identified during routine mail screening procedures as potential explosive devices and were appropriately handled as such.
The Time Warner Center, the Manhattan office and shopping center where CNN's offices are located, is now reopening.
But the building was evacuated when authorities found the explosive device addressed to former CIA Director and critic of President Trump, John Brennan in the CNN mail room.
In addition to an envelope, officials say it contained a white powdery substance.
President Trump condemned the attacks and said, "The full weight of our government will conduct this investigation and bring those responsible for these despicable acts to justice."
President Trump added during times like this, we must come together as a nation.
"We need to send one clear, unmistakable message that these acts or threats of political violence of any kind have no place in the United States of America," said President Trump.
Another suspected explosive device was found at the office of Florida Democrat US Rep. Debbie Wasserman Schultz.
Whoever sent the explosives used Wasserman Schultz as the return address. It is believed that the package found at her office was sent to former Attorney General Eric Holder, but returned to sender because it had the wrong address.
A sixth suspicious package, sent to California Democrat US Rep. Maxine Waters, was intercepted at a Congressional mail facility and is under investigation.
Retired FBI explosive expert, Tom Thurman, says authorities will now try to disassemble these suspected bombs and examine the possible sources of the components.
He says they will look for anything to tie an individual to them - some sort of signature.
"They will conduct biometric examinations, like fingerprints, possible DNA that could be left on some of the components. If it's an electrical system, the wires, batteries, battery holders, switch will also be examined," said Thurman.
Family Research Council Executive Vice President, retired Lt. General Jerry Boykin watched the news closely.
It was back in 2012 when a terrifying attack took place at the conservative group's D.C. office when a gunman fired several shots inside the lobby injuring a security guard.
"This whole thing of sending bombs to people is the next step of a total meltdown of our society as it related to political discourse and opinions," said retired Lt. Gen Boykin.
Right now, the National Counterterrorism Center said officials have not yet reached a conclusion if there is a connection to foreign terrorism with the suspicious packages or if it's a domestic terrorist.
No suspects have been named or arrested.