The US mail bomb scare has widened as police seized three more suspicious packages - two addressed to former vice president Joe Biden and one to actor Robert De Niro.
Officers said the items were similar to crude pipe bombs sent to former president Barack Obama, Hillary Clinton and CNN.
Another device addressed to US representative Maxine Waters was intercepted in Los Angeles on Wednesday.
- Read more: Pipe bombs sent to former US president Obama and the Clintons
- Read more: Counter terrorism specialist blames Donald Trump for spate of pipe bombs sent to prominent US politicians
The first crude bomb to be discovered had been delivered on Monday to the suburban New York compound of George Soros, a liberal billionaire and major contributor to Democratic causes. Mr Soros has called Mr Trump's presidency "dangerous".
The device addressed to Mr Biden, who has also criticised Mr Trump, was intercepted at a Delaware mail facility.
None of the devices exploded and no one was injured but the packages - sent to prominent Democrats critical of President Donald Trump - heightened nationwide tensions two weeks before congressional mid-term elections.
Trump blames 'fake news'
Mr Trump blamed “fake news” for fuelling “anger” in society.
"A very big part of the Anger we see today in our society is caused by the purposely false and inaccurate reporting of the Mainstream Media that I refer to as Fake News," he tweeted. "It has gotten so bad and hateful that it is beyond description. Mainstream Media must clean up its act, FAST!"
Former CIA director John Brennan, the target of one package sent to CNN where he has been a contributor, fired back.
"Stop blaming others. Look in the mirror," Mr Brennan tweeted. "Your inflammatory rhetoric, insults, lies, & encouragement of physical violence are disgraceful. Clean up your act....try to act Presidential."
'There's always going to be a nutter'
Watch: Counter-terror expert Simon Trundle says Donald Trump's rhetoric could have inspired 'nutters'
Counter-terror expert Simon Trundle told talkRADIO’s Julia Hartley-Brewer that responsibility for the crude bombs had to "land back at Donald Trump's doorstep" because he had openly criticised Clinton and Obama, calling them "enemies of the state".
"How did they get motivated to do this? I'm afraid that has to land back at Donald Trump's doorstep, because for two years now he's been going round calling these people enemies of the state, getting his people to shout ‘lock her up’, attacking Barack Obama," he said.
"It's easy to inspire a mad man or woman, or a group, point a target out to them and claim no responsibility when they act upon it.
"When you stoke a narrative of separation and they're the enemy and we're the heroes… there's always going to be a nutter or two out there that suddenly thinks he or she has been given justification by their leaders."