NEW YORK: Pipe bombs were sent to Barack Obama, prominent Democrats and CNN - all hate figures for backers of President Donald Trump - in a coordinated plot to "terrorise" ahead of polarising US elections, officials said Wednesday.
Hillary Clinton was among some of the most high-profile Democrats targeted with America bitterly divided ahead of Nov 6 elections seen as a referendum on the Republican president.
CNN is well known for its robust coverage of the Trump administration and is routinely singled out for harsh words by the president, who succeeded Obama and defeated Clinton in 2016. Signs at his rallies condemn the network.
The spree of bomb alerts was kicked off Monday with a device found at the New York home of billionaire liberal donor George Soros. "So far the devices have been what appear to be pipe bombs," said FBI agent Bryan Paarmann.
"It appears that an individual or individuals sent out multiple similar packages," he added.
Trump strongly condemned the events and promised the perpetrators would be capture and tried.
Other targets included prominent African American Democrats -- Obama's former attorney general Eric Holder and Maxine Waters, a lawmaker from California -- both them outspoken Trump critics.
All the packages reportedly included the return address of Debbie Wasserman Schultz, former chairwoman of the Democratic National Committee.
A suspicious device sent to the Manhattan office of New York's Democratic Governor Andrew Cuomo turned out to be a false alarm, as did a scare in the offices of rising star Senator Kamala Harris.
Trump, speaking from the White House, used his presidential perch to appeal for unity, saying acts of political violence have "no place" in the United States. Critics on the left accuse his rhetoric-laden presidency of emboldening right-wing extremists and condoning violence.
"At these times we have to unify and send one very clear and strong message that acts of political violence of any kind have no place in the United States of America," he told an event on the opioid crisis.
First Lady Melania Trump opened the White House gathering by denouncing "cowardly attacks" and condemning "all who choose violence".
White House Press Secretary Sarah Sanders said anyone responsible would be "held accountable to the fullest extent of the law" as the Secret Service, the FBI and local police plunged into a full-scale criminal investigation.
CNN evacuated its New York bureau Wednesday after the pipe bomb together with an envelope containing white powder was found in the mailroom. A bomb squad secured the device and removed it for investigation, police said.
The packaging was addressed care of CNN to former CIA director John Brennan, who has worked as a television analyst but not for the channel.
The Secret Service intercepted the package addressed to Clinton at the home she shares with her husband, former president Bill Clinton, north of Manhattan on Tuesday, and a second package addressed to Obama's Washington home on Wednesday.
There has been no claim of responsibility and no one was yet thought to have been arrested.
Clinton, who has remained an outspoken political force despite her stunning loss to Trump in the 2016 election, thanked the Secret Service and raised concerns about what she called a "troubling time" in America.
"It's a time of deep divisions, and we have to do everything we can to bring our country together," she said.
In New York, Mayor Bill de Blasio condemned "an effort to terrorise" as he appealed to all elected officials, from the top down, to refrain from encouraging violence.
He didn't mention Trump by name, although the president came under a torrent of criticism for recently endorsing the body slamming of a reporter.
"Unfortunately this atmosphere of hatred is contributing to the choices people are making," said de Blasio. "The way to stop that is turn back the other way, to bring down the temperature, to end any messages of violence against people we disagree with and this has to start at the top."
Top Democrats reacting to the attacks later accused Trump of condoning violence and dividing the US.
The Secret Service said the packages were "immediately identified during routine mail screening procedures" and that neither Clinton or Obama were ever at risk of receiving them.
Republican lawmakers followed the White House in issuing condemnations, just over a year after a shooter angry about Trump shot four people at a congressional baseball practice near Washington.
"Violence and terror have no place in our politics or anywhere else," tweeted senior Republican lawmaker Steve Scalise, who was seriously injured at the baseball practice in June 2017.
The top Republican lawmaker, Mitch McConnell, slammed "attempted acts of domestic terrorism".
Soros, the target of the first device, has long been a hate figure for right-wing groups and lives in Bedford, New York, not far from the Clintons.
The 88-year-old billionaire is one of the world's richest men who supported Clinton in 2016, and has been accused by nationalists the world over of sponsoring protests and seeking to push a liberal, multicultural agenda.
Earlier this month, Trump accused Soros of paying demonstrators to protest against the nomination of Supreme Court Justice Brett Kavanaugh, who was accused of attempted rape in high school.
Soros has also been falsely accused of funding the caravan of migrants moving north from Honduras through Mexico en route to the US border.
Trump, hitting his anti-immigration agenda hard on the campaign trail, has similarly blamed Democrats for inciting the caravan.