Barack Obama, Hillary Clinton and CNN's offices have all been sent explosive devices in the mail
Joe Biden and Robert De Niro latest targets of serial pipe bomb package
Former vice president Joe Biden and actor Robert De Niro are the latest critics of US President Donald Trump to receive packages containing possible explosive devices.
A package address to Mr Biden was seized in a US postal service building in Delaware on Thursday and in New York authorities are investigating a suspicious package sent to Tribeca Grill, a restaurant owned by actor Robert De Niro.
Donald Trump, who has frequently been blamed for stoking anger at his opponents and the media, condemned the attempted attacks on Wednesday.
“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 at the White House.
Mr Trump sought to blame the media for creating what he has said is a hostile environment at a midterm election campaign rally in Wisconsin on Wednesday night. The President renewed his criticisms on Twitter on Thursday, saying anger in the US is caused by "purposely false and inaccurate reporting".
No one has been injured and it is not clear if the pipe bombs were able to explode or if they were fakes.
All of the packages have been delivered in manilla brown envelopes with bubble wrap inside, with the address of former chairwoman of the Democratic National Committee Debbie Wasserman Schultz as the return address.
One package, addressed to former Attorney General Eric Holder was delivered to Mrs Wasserman Schultz as her name was listed as the return address and the package could not be delivered.
An FBI-led Joint Terrorism Task Force is working with federal, state and local authorities to investigate the source of the packages. The motives for the spree are unclear, but all of the recipients have been vocal critics of Mr Trump, often the source of public criticism by the president, leading to vilification by the political right.
The first package was discovered at the home of billionaire philanthropist George Soros on Monday. On Wednesday, the US Secret Service announced they had found similar packages addressed to former first lady Hillary Clinton and former US president Barack Obama.
At least five other packages were primarily sent to locations in New York and Washington, but they were also found at locations in Los Angeles and Florida.
Mr De Niro has been a vocal critic of President Trump, drawing a standing ovation after an expletive-filled speech at the Tony awards in June. Mr Trump responded on Twitter, calling him a "very low IQ individual".