He is being questioned by Federal Bureau of Investigation agents with the Joint Terrorism Task Force since his arrest this morning at about 10 a.m.
Though none has exploded, they comprise one of the biggest bombing threats in the United States in decades. "I am confident that this person or people will be brought to justice". "I'm committed to doing everything in my power as President to stop it".
The arrest was made at an AutoZone store in Plantation, Florida. A total of 10 packages containing suspected explosive devices were found between Tuesday and Thursday.
Photographs circulating on social media showed what appeared to be the same van that was taken from the scene, identifiable by some of the same stickers.
Court documents later established that the van, which was covered with pro-Trump and anti-CNN images, belonged to Sayoc; a former attorney who had represented him told NPR Sayoc has been living in a van for some time.
Earlier today, authorities said suspicious packages addressed to New Jersey Sen.
Mr Clapper said he is not surprised he has been targeted with a suspicious package.
Law enforcement officials told The Associated Press that the devices, containing timers and batteries, were not rigged to explode upon opening.
Authorities acknowledged additional undelivered packages could still be in the mail.
A police spokesman said the parcel "was similar to explosive packages that had been publicised".
Trump tweeted a baseless conspiracy theory on Friday suggesting that the bombs were a plot to thwart GOP momentum in the midterms. Very unfortunate, what is going on. One was also addressed to the actor Robert De Niro, a harsh Trump critic.
"I'm extremely grateful to the courageous women and men in law enforcement who swiftly apprehended this suspect and are working tirelessly to keep us safe", Wasserman Schultz said in a statement Friday.
New details about the devices came as the four-day mail-bomb scare spread nationwide, drawing investigators from dozens of federal, state and local agencies in the effort to identify one or more perpetrators.
A law enforcement source said the package addressed to Mr Biden was intercepted at a DE mail facility and was similar to the others.
Before the package arrived there, it was rerouted through the Opa-locka mail sorting facility, the Herald reports. "They originated, some of them, from Florida", she said during an interview with Fox News Channel on Thursday.
Soros, the target of the first device, has always been a hate figure for right-wing groups and lives in Bedford, New York, not far from the Clintons.
The FBI, which is leading the investigation into the packages, has only confirmed the existence of 11 packages and has not released any information about suspects or any potential motivation for the mailings. Debbie Wasserman Schultz of Florida, the sources said.
Packages to Biden were found at two different post offices, one in New Castle and the other in Wilmington.
One lead being pursued by investigators is that some of the devices may have been mailed from south Florida, but officials were cautious Thursday and urged the public to call in with tips from anywhere.
Tribeca Enterprises co-founder Jane Rosenthal said Thursday that the building was evacuated after the package was found, but that it has been re-opened. The source of the packages is under investigation, and authorities have not said whether there is a motive. Sources told CBS News that the package sent to Clapper was found at a postal facility in New York City.
Investigators have declined to say whether the devices were built to be functional.
Each bore a computer-printed address label and six "Forever" postage stamps.
Trump initially responded to the acts - which New York governor Andrew Cuomo and New York City Mayor Bill de Blasio referred to as acts of "terrorism" - by calling for the nation to "unify" amid the still-unknown perpetrator's "egregious conduct" he deemed "abhorrent to everything we hold dear and sacred as Americans".
Many responsible democrats accuse on the contrary, the u.s. president of "condone violence" and to stir up divisions.