Updated at 4:22 p.m. ET

At least six suspicious packages — some containing explosive devices — have been sent since Monday to several leading Democratic figures in multiple states and to CNN in New York, triggering a massive investigation.

Some of the devices "appear to be pipe bombs," John Miller, NYPD deputy commissioner of intelligence and counterterrorism, said at a news conference Wednesday.

The Secret Service said it had intercepted two suspicious packages that were addressed to former Secretary of State Hillary Clinton in Westchester County, N.Y., and former President Barack Obama's residence in Washington, D.C.

The packages addressed to Clinton and Obama contained explosive devices similar to one found Monday at the Bedford, N.Y., home of billionaire George Soros — a frequent contributor to Democratic and progressive causes. An explosive ordnance disposal team did a controlled detonation and destroyed the package.

The package sent to CNN contained what "appeared to be a live explosive device" as well as an "envelope containing white powder," New York City Police Commissioner James O'Neill said at the news conference.

Authorities also intercepted a suspicious package addressed to former U.S. Attorney General Eric Holder, two people familiar with the matter told NPR's Carrie Johnson on Wednesday.

The package for Holder was mailed to his law firm's office in Washington, D.C., one person told Johnson, and for reasons that are unclear was sent back to the return address. That address was for the Sunrise, Fla., office of U.S. Rep. and former Democratic National Committee Chairwoman Debbie Wasserman Schultz, Johnson reports.

Police in Sunrise said Wednesday morning that they were "working on an investigation of a suspicious package near Sawgrass Corporate Parkway," which is near the office used by Wasserman Schultz.

Also Wednesday, California Democratic Rep. Maxine Waters said U.S. Capitol Police intercepted a suspicious package targeting her office. Waters thanked law enforcement investigating the package and said in a statement that "I unequivocally condemn any and all acts of violence and terror."

President Trump, speaking at the White House, said that the "safety of the American people is my highest and absolute priority."

"As we speak, the packages are being inspected by top explosive experts, and a major federal investigation is now underway," Trump said. "The full weight of our government is being deployed to conduct this investigation and bring those responsible for these despicable acts to justice. We will spare no resources or expense in this effort."

The packages addressed to Clinton and Obama "were immediately identified during routine mail screening procedures as potential explosive devices and were appropriately handled as such," the Secret Service said in a statement Wednesday. "The protectees did not receive the packages nor were they at risk of receiving them."

The package to Clinton was intercepted late Tuesday, and the package to Obama was intercepted early Wednesday morning.

Clinton responded to the incident by saying "We are fine" and thanking the men and women of the Secret Service. Speaking at a Florida fundraiser for Donna Shalala, a former HHS secretary who is running for Congress, she said it is a "troubling time" and that "we have to do everything we can to bring our country together."

The NYPD's Miller stated that security officials were visiting offices of elected officials and media and television outlets Wednesday to inform them about what to watch for — and, in fact, he says NYPD officials were in the CNN mailroom when the suspicious package was discovered.

CNN broadcast images of a yellow mailing envelope addressed to former CIA Director John Brennan and Time Warner Center, also with a return address for Wasserman Schultz in Sunrise, Fla.

The explosive device inside was safely removed by the bomb squad using a "bomb truck," according to Miller, and authorities were working to transport it to FBI laboratories for further investigation, along with the other devices.

In a statement, White House press secretary Sarah Sanders said, "We condemn the attempted violent attacks recently made against President Obama, President Clinton, Secretary Clinton, and other public figures." She added, "These terrorizing acts are despicable, and anyone responsible will be held accountable to the fullest extent of the law."

"These attempted attacks that have been made are beyond criminal, they are acts of pure terror," said House Majority Whip Steve Scalise, who was shot and gravely wounded during an attack on a baseball practice of Republican lawmakers in 2017. "Violence and terror have no place in our politics or anywhere else in our society."

With regard to the Clinton and Obama packages, the Secret Service says it is investigating the incidents, using "all available federal, state, and local resources to determine the source of the packages and identify those responsible."

Like the Clintons, Soros lives in Westchester County, N.Y. The left-leaning billionaire philanthropist is the founder of the Open Society Foundations, which work to "build vibrant and tolerant democracies whose governments are accountable to their citizens." (The OSF has been a financial supporter of NPR.)

When the Obama family left the White House, they rented a house in D.C.'s Kalorama neighborhood that they purchased months later. The couple have said they want to remain in Washington, D.C., until their youngest daughter, Sasha, finishes high school.

There also were multiple reports of suspicious packages on Wednesday that turned out to be false alarms.

Some media outlets had suggested that the White House had received a suspicious package, but the Secret Service later clarified that "reports of a third intercepted package addressed to the WH are incorrect."

New York Gov. Andrew Cuomo told reporters at Wednesday's news conference that "a device has been sent to my office in Manhattan, which we were just informed about." Cuomo's office later said that "a preliminary investigation on the package at Gov. Cuomo's office shows it is computer files on the hate group, The Proud Boys, who recently appeared in New York."

The downtown San Diego office of The San Diego Union-Tribune was briefly evacuated because of concerns about a possible suspicious package. That was later determined to be a false alarm and police have given the all-clear.

This is a breaking news story. As often happens in situations like these, some information reported early may turn out to be inaccurate. We'll move quickly to correct the record, and we'll only point to the best information we have at the time.