The Associated Press reported two packages were sent to Biden, and one was sent to De Niro.
The explosive devices believed to be pipe bombs were sent to the homes of the Clintons and the Obamas, as well as other politicians and to CNN headquarters in New York City Wednesday.
Authorities say a potentially workable explosive device was found at a facility near the Chappaqua home of former President Bill Clinton and former Secretary of State Hillary Clinton. It was discovered sometime after 1 a.m. by those who check the Clintons' mail and was addressed to the former first lady, who is currently in Florida for a fundraiser.
"Many of you and many others across our country have asked after me and my family, and I'm very grateful for that," she said in Coral Gables. "We are fine, thanks to the men and women of the Secret Service who intercepted the package addressed to us long before it made its way to our home. Every day, we are grateful for their service and commitment."
Former President Clinton was at home at the time the package was found, according to a source familiar with the situation who stressed that the package was screened and discovered away from the residence and was never close to Clinton.
Later Wednesday morning, an explosive device was also discovered at former President Barack Obama's home in Washington, DC. That one was addressed to the former president.
Then, at 9:38 a.m., a CNN mail room employee called 911 from the Time Warner Center in Columbus Circle to report a suspicious device. The NYPD bomb squad responded and evacuated the building.
The object appears to be a small pipe bomb with wires extending from it, addressed to former CIA Director John Brennan (who is a contributor for NBC). It was removed from the building at 11:37 a.m. and taken to a remote location to be detonated.
The NYPD said that in addition to the explosive device, an envelope containing white powder was also discovered at the Time Warner Center. Mayor Bill de Blasio called it an act of terrorism.
"What we saw here today was an effort to terrorize," he said. "This clearly is an act of terror, attempting to undermine our free press and leaders of this country through acts of violence. I want to make very clear that the people of New York City will not be intimidated, that we are going to go about our lives undeterred because the very concept of terrorism to change us, and we will not allow that to happen."
A pipe bomb was also sent to former Attorney General Eric Holder, but the package never made it to its destination due to a delivery error and was bounced back to the return address. That address was listed as Rep. Debbie Wasserman Schultz's office in Sunrise, Florida, which was briefly evacuated.
A law enforcement official says the pipe bombs were packed with powder and shards of glass. The official says the devices were made from PVC pipe that was about six inches long and covered with black tape.
Earlier this week, an explosive device was found in the mailbox of philanthropist and billionaire George Soros, who also lives in Westchester County.
The FBI said all the packages are being analyzed at the bureau's lab in Virginia. The agency said each package had a return address of "DEBBIE WASSERMAN SHULTZ," a misspelling of the Florida congresswoman's name, and had printed address labels and six stamps.
All of the bombs and packages were similar, with American flag stamps on the envelopes and the bombs wired to a digital clock with a battery to spark an explosion.
The White House quickly condemned the attacks aimed at Democrats and perceived foes of the administration.
"Acts or threats of political violence have no place in the United States," President Donald Trump said. "This egregious conduct is abhorrent."
Trump said he received a briefing from federal officials on what he called "despicable acts." He promised "a major federal investigation" and urged the nation to unify.
"We're extremely angry, upset, unhappy about what we witnessed this morning and we will get to the bottom of it," he said. "That's a very bipartisan statement."
Contrary to prior reports, the Secret Service confirms no suspicious package was sent to the White House. Additionally, a suspicious package at the New York City office of Gov. Andrew Cuomo was confirmed to be a flash drive from the far-right group The Proud Boys.