A man has been taken into custody Friday in Florida by law enforcement officials investigating mail bombs that had been addressed to prominent Democrats and critics of President Trump, the FBI said.

The announcement came hours after officials intercepted packages addressed to U.S. Sen Cory Booker (D., N.J.) and former national intelligence director James Clapper, bringing the number of packages recovered in the past five days to 12.

The FBI announcement provided no other details, but news reports identified the man as Cesar Sayoc, 56, of Aventura, Fla.

Trump, in an appearance at a Young Black Leadership Summit, said, "an incredible job by law enforcement" led to the arrest.

Saying the mail bombs were "despicable and have no place in our country," the president said, "we must never allow political violence to take root in our country."

Trump, who earlier complained on Twitter that "this 'BOMB' stuff "was interfering with GOP momentum in the midterm elections, said the government would prosecute anyone charged in connection with mail bombs "to the fullest extent of the law."

The Miami Herald reported that Sayoc is a catering company manager who was sentenced to one year of probation for making a bomb threat in 2002. He has appeared in photos wearing a red Make America Great Again cap.

Earlier, TV helicopter video showed FBI agents in Plantation, Fla., using a blue tarp to cover a white van, which had its windows covered with stickers, before it was loaded onto a trailer.

Bob Cesca, a political podcaster, posted a photo on Twitter of the van before it was wrapped up.

The FBI said the package for Booker, which was addressed to his Camden, N.J., office, was found in Florida, where officials have been focusing on a mail-sorting facility in their hunt for the suspect.

Law enforcement officials said the package to Clapper was found at a New York City postal facility and had been addressed to CNN's Manhattan office, from which police removed another package earlier this week. Clapper is a CNN contributor, as is former CIA director John Brennan, to whom the first package had been addressed.

"This is definitely domestic terrorism, no doubt about it my mind," Clapper said on CNN after the package was found.

Booker's office declined comment and referred questions to law enforcement agencies.

Police and federal agents with dogs in the meantime were seen at the Delaware River Port Authority building on the Camden waterfront where Booker has an office.

DRPA chairman John Hanson said there was no threat and no need to evacuate the building. Officials made a sweep of the site in an "abundance of caution" and found nothing suspicious, he said.

"It's just business as usual here," Hanson said.

Law enforcement officials told the Associated Press that the devices, containing timers and batteries, were not rigged like booby-trapped package bombs that would explode upon opening. But they were uncertain whether the devices were poorly designed or never intended to cause physical harm.

A search of a postal database suggested at least some may have been mailed from Florida, one official told the AP. Investigators were honing in on a postal facility in Opa-locka, Florida, where they believe some of the packages originated, another official said.

Homeland Security Secretary Kirstjen Nielsen, in an interview Thursday night with Fox News Channel, acknowledged that some of packages originated in Florida.

One Thursday, officials intercepted packages addressed to former Vice President Joe Biden and actor Robert DeNiro.

Targets in the now-five-day pipe bomb scare also have included former President Barack Obama, Hillary Clinton, CNN, and Rep. Maxine Waters of California.

The envelopes used to send the devices have all been similar, officials say.

Staff writer Andrew Seidman contributed to this story.