Explosive devices have been delivered to former US President Barack Obama, 2016 US presidential candidate Hillary Clinton, and CNN, amongst others ahead of the 6 November midterm elections.
The packages were filled with suspected crude pipe bombs clothed in black tape and the envelope stated the return address of Democratic Florida congresswoman Debbie Wasserman Schultz.
Several Democrats and critics of President Donald Trump were targeted, but none of the bombs detonated and no one has been injured.
An investigation has been launched to find the culprits of such actions which are the latest sign of an internally divided country.
The Democrats affected include former President Barack Obama, his Vice-President Joe Biden, former presidential candidate Hillary Clinton, former Attorney General Eric Holder, and Congresswoman Maxine Waters.
Former CIA director John Brennan and billionaire George Soros were also the subject of attacks.
The network of targeted attacks was discovered following the Secret Service’s interception of the package sent to Obama’s home in Washington. While an identical package sent to Mrs Clinton was discovered at a mail sorting office before it reached her home where former president Bill Clinton was present.
The packages “were immediately identified during routine mail screening procedures,” the Secret Service said. They were treated as “potential explosive devices and were appropriately handled as such.”
The package destined for Mr Brennan triggered the evacuation of the Time Warner Centre in New York after it was found in a CNN mailroom. Meanwhile, the package addressed to Mr Soros is suspected to have been delivered by hand.
President Donald Trump has promised a full investigation into the matter. “In these times, we have to unify, we have to come together, and send one very clear, strong, unmistakable message that acts or threats of political violence of any kind have no place in the United States of America,” he said.
This is not the first time political figures in the US have been targeted. Indeed, earlier this month a package suspected to contain the poison ricin was addressed to Mr Trump.