By Agence France-Presse
Democrat and Trump foe Hillary Clinton was one of those targeted just days before the bitterly divided country votes November 6 in elections seen as a referendum on the Republican president.
CNN is known for its robust coverage of the Trump administration and for constantly provoking the ire of the president, who succeeded Obama and defeated Clinton in 2016. Signs at his rallies condemn the network.
The spree of bomb alerts 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.
"Whether it's one person or a network, not really sure at this point," New York police chief James O'Neill told CNN, saying he expected those responsible to be identified and arrested within the next few days.
At least six suspicious packages were sent in New York, Washington and Florida, including to prominent African American Democrats -- Obama's former attorney general Eric Holder and Maxine Waters, a lawmaker from California.
They were sent in manila envelopes with bubble wrap, marked with computer-printed address labels. Each listed Debbie Wasserman Schultz, former chairwoman of the Democratic National Committee, as the sender.
The US president appealed for unity in extremely brief remarks, saying "acts of political violence" have "no place in the United States."
On Twitter, #MAGABomber trended in the United States as users flooded the microblogging site with accusations that Trump had incited the attempted attacks and highlighting the toxic remarks he has leveled against the targets in the past.
Liberal and left-wing critics accuse his rhetoric-laden "Make America Great Again" presidency of emboldening right-wing extremists. He has endorsed the body-slamming of a reporter and denounces critical press as "fake news".
- 'Words matter' -
"There is a total and complete lack of understanding at the White House about the seriousness of their continued attacks on the media," said CNN president Jeff Zucker.
"Words matter. Thus far, they have shown no comprehension of that."
CNN evacuated its New York bureau Wednesday after the pipe bomb was found in the mailroom together with an envelope containing white powder. 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 appeared on the channel as a guest and is perhaps Trump's toughest critic from the national security community.
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 known to have been arrested.
Clinton, who has remained an outspoken political force despite her stunning loss to Trump in the 2016 election, 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.
Top Democrat lawmakers Nancy Pelosi and Chuck Schumer accused Trump of condoning "physical violence and dividing Americans."
In New York, Mayor Bill de Blasio condemned "an effort to terrorize" and appealed to all elected officials, from the top down, to refrain from encouraging violence.
"Unfortunately this atmosphere of hatred is contributing to the choices people are making," he said.
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 is one of the world's richest men and supported Clinton in 2016. He has been accused by nationalists of sponsoring protests and seeking to push a liberal, multicultural agenda.
Earlier this month, Trump accused Soros of paying demonstrators to protest against Brett Kavanaugh, whose nomination to the Supreme Court was almost derailed after he was accused of attempted rape while 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.