SUNRISE (CBSMiami/CNN) - Congresswoman Debbie Wasserman Schultz spoke out about the string of suspicious packages sent to political figures and celebrities across the country.
Authorities believe several of the packages went through a processing and distribution facility in Opa-locka, Florida.
The facility handles mail that is incoming and outgoing from South Florida.
It is located at 5500 Northwest 142nd Street in Opa-locka.
CBS News is reporting that law enforcement sources said the FBI is at the facility in Opa-locka.
Investigators are scrutinizing camera footage at the self-mailing kiosk machines inside the facility, per CBS News.
Investigators are also combing through surveillance video footage at the facility and the nearby businesses.
They are also canvassing the area.
CBS4 has learned that the Miami-Dade Police Department is assisting the FBI investigation at the facility.
The Miami-Dade Police bomb squad is also at the facility.
Senior law enforcement sources tells CBS4 that the sweep was requested by the FBI "out of an abundance of caution" and that no devices have been found.
Speaking at an event with Florida Gubernatorial candidate Andrew Gillum, Wasserman Schultz spoke publicly for the first time about the suspicious packages.
"The last couple of days have been trying for a couple of us to say the least," she said. "My brave staffers and I saw those weapons of hate up close this week. I know everyone in this room and others will always choose love, compassion, and honest communication to make our world a better place."
"We will never be cowed into submission by people who hate," she added. "Never, never."
WATCH: Debbie Wasserman Schults addresses suspicious packages at campaign event:
This news comes on a day when three more suspicious packages bearing the return address of Wasserman Schultz's office in Sunrise have been recovered by law enforcement.
The latest recipients were former Vice President Joe Biden and actor-director Robert De Niro.
Two packages addressed to Biden were intercepted at Delaware mail facilities in New Castle and Wilmington. They were considered suspicious due to its similarities to other packages sent this week to prominent Democrats and CNN.
Biden owns homes Greenville and Rehoboth Beach, Delaware.
High-profile politicians and celebrities targeted by pipe bombs:
Also on Thursday, a suspicious package addressed to Robert De Niro was reported at the Manhattan building where his production company is based.
Law enforcement officials say the suspected explosive device sent to De Niro may have been sitting in the mailroom of his building for a day or more before it was discovered.
A person affiliated with the Tribeca Film Center was off work when he saw an image on the Internet and elsewhere of the package containing a crude pipe bomb sent to CNN. That person, who has a background in law enforcement, recalled seeing a similar package at the film center mailroom earlier and reported it to police. The NYPD bomb squad X-rayed the parcel and decided to remove it for investigation. That package was placed into a bomb disposal truck and driven to an NYPD firing range in the Bronx.
De Niro has been a fierce critic of President Donald Trump.
At least ten explosive devices have been sent to Democratic political figures across the country, including the CNN headquarters in Manhattan.
A law enforcement official told CBS News investigators are looking at Florida as possibly where the letter packages were mailed from.
"A lot of arrows pointing to Florida," the official told CBS News.
A second law enforcement official told CNN on Thursday that federal investigators were in Florida, chasing down leads.
All packages have had a return address of "Debbie Wasserman Shultz," the FBI said. On most of the packages her last name was misspelled.
"I have been in direct contact with the FBI and other law enforcement officials who are working tirelessly on this investigation, and I am grateful for their efforts to keep us safe. We will not be intimidated by this attempted act of violence. This appalling attack on our democracy must be vigorously prosecuted, and I am deeply disturbed by the way my name was used," Wasserman Schultz said in a statement.
With less than two weeks until Election Day, Senator Marco Rubio is calling the actions of the sender not only immoral but a crime.
"I know a lot of partisans, I know a lot of passionate liberals, I know a lot of passion of conservatives, but I don't know any of them that are going to make bombs and try to kill people on the other side. They may heckle you, they'll definitely vote against you but they would never make a bomb to try and kill you, The reason is simple, in America we don't do that, we don't have to because we have elections, we have ballots, we are here today to ask people to vote against those you disagree with, not to hurt them."
Law enforcement authorities are treating the series of bombs as a domestic terror matter and are advising the public to remain vigilant.
The motive is unknown, but the recipients are all prominent targets of right-wing criticism and, in many cases, of President Donald Trump himself. The package found at CNN's New York bureau in the Time Warner Center was addressed to former CIA Director John Brennan.
Investigators in New York are poring over video from local business and other surveillance cameras in the area near the Time Warner Center in search of the courier who delivered the suspicious package to the building's mailroom.
Devices sent to former President Barack Obama, Hillary Clinton, former Attorney General Eric Holder, California Democratic Rep. Maxine Waters, and Democratic donor George Soros showed the presence of a sulfur substance, which could have exploded, a law enforcement official said. The packages were also stuffed with shards of glass.
A suspicious package addressed to Waters was intercepted at a House mail facility, two sources told CBS News. The Los Angeles Police Department said it was investigating another package found at a mail facility near Downtown Los Angeles.
A package that was originally addressed to former Attorney General Eric Holder didn't arrive at the address it was intended for and was rerouted to the return address on the label - Wasserman Schultz's office in Sunrise which was evacuated Wednesday until the package was safely removed. The congresswoman was not in the office at the time.
The FBI's counterterrorism division is leading the investigation into the packages and the agency says it's possible additional packages were mailed to other locations. All of the devices are believed to be pipe bombs, inherently unstable, and at risk of being set off just by handling.
At the White House, Trump vowed Wednesday that "we will spare no resources or expense" to pursue the perpetrator. On Thursday, he blamed the media for much of the "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. It has gotten so bad and hateful that it is beyond description. Mainstream Media must clean up its act, FAST!
— Donald J. Trump (@realDonaldTrump) October 25, 2018
Although the President has often derided the media as "fake news," even labeling reporters the "enemy of the people," Thursday's tweet is especially striking in the wake of potential attacks on a major media outlet and political figures who have criticized him.
Former CIA Director John Brennan, who was an intended recipient of one of the packages, responded to Trump's tweet, telling the President to "stop blaming others" and "look in the mirror."
"Your inflammatory rhetoric, insults, lies, (and) encouragement of physical violence are disgraceful," Brennan wrote on Twitter to the President. "Clean up your act....try to act Presidential. The American people deserve much better."
He added that the President's "critics will not be intimidated into silence."
(©2018 CBS Broadcasting Inc. All Rights Reserved. CNN contributed to this report.)
for more features.