2 suspicious packages recovered, addressed to former DNI James Clapper and Sen. Cory Booker

MIDTOWN MANHATTAN -- Suspicious packages addressed to New Jersey Sen. Cory Booker and former National Intelligence Director James Clapper - and similar in appearance to pipe bomb devices sent to other prominent Democrats - have been intercepted, the FBI said Friday, as investigators scrambled from coast to coast to locate the culprit and motives behind a bizarre plot aimed at critics of President Donald Trump.

The discoveries brought to 12 the total number of devices addressed in recent days to Democratic figures including former President Barack Obama, former Vice President Joe Biden and Hillary Clinton.

The FBI said the package to Booker was intercepted in Florida. The one discovered at a Manhattan postal facility was addressed to Clapper c/o CNN. An earlier package had been sent to former Obama CIA Director John Brennan in care of CNN in New York.

Investigators were analyzing the innards of the crude devices to reveal whether they were intended to detonate or simply sow fear just before Election Day.

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 said. Investigators are homing in on a postal facility in Opa-locka, Florida, where they believe some of the packages originated, another official said.

The officials spoke on condition of anonymity because they were not authorized to discuss the ongoing investigation by name.

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

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.

The targets have included Obama, Hillary Clinton, CNN and Rep. Maxine Waters of California. The common thread among them was obvious: their critical words for Trump and his frequent, harsher criticism in return.

At a press conference Thursday, officials in New York would not discuss possible motives or details on how the packages found their way into the U.S. postal system. Nor would they say why none of the packages had detonated, but they stressed they were still treating them as "live devices."

"As far as a hoax device, we're not treating it that way," police Commissioner James O'Neill said.

Details suggested a pattern - that the items were packaged in manila envelopes, addressed to prominent Trump critics and carried U.S. postage stamps. The devices were being examined by technicians at the FBI's forensic lab in Quantico, Virginia.

The packages stoked nationwide tensions and fears as voters prepared to vote Nov. 6 to determine partisan control of Congress - a campaign both major political parties have described in near-apocalyptic terms. Even with the sender still unknown, politicians from both parties used the threats to decry a toxic political climate and lay blame.

CNN didn't immediately respond to messages seeking comment before business hours Friday.

The list of bombing targets spread from New York, Delaware and Washington, D.C., to Florida and California.

The explosive devices were packed in envelopes with bubble-wrap interiors bearing six American flag stamps and the return address of Florida Rep. Debbie Wasserman Schultz, the former chairwoman of the Democratic National Committee.

The bombs seized Wednesday were about 6 inches (15 centimeters) long and packed with powder and broken glass, according to a law enforcement official who viewed X-ray images. The official said the devices were made from PVC pipe and covered with black tape. At the New York briefing, authorities confirmed that at least some of the packages were distributed through the U.S. mail, and cautioned that there could be additional devices in the postal system. They said investigators searching for more suspicious parcels had not found any during the previous eight hours.

David Chipman, a retired federal ATF agent and now senior policy adviser for the Giffords Center, said the details revealed telltale signs that could help guide investigators.

The tape on the pipe is "an investigator's dream," he said, recalling a case in Texas that was solved because the fibers on the tape were traced to the bomber's dog. He said bombers tend to plot methodically.

"This is someone sitting down and spending time thinking about what they're going to do to someone else. And some people like to relish that," he said.

The new packages discovered Thursday set off a new wave of alarm.

A retired New York police detective working in security in De Niro's Manhattan office called police after seeing images of a package bomb sent to CNN and recalling a similar package addressed to the actor, officials said.

The packages addressed to Biden were intercepted at Delaware mail facilities in New Castle and Wilmington, according to a law enforcement official who, like others, wasn't authorized to discuss the investigation and spoke on condition of anonymity.

The first crude bomb to be discovered was delivered Monday to the suburban New York compound of George Soros, a liberal billionaire and major contributor to Democratic causes. Soros has called Trump's presidency "dangerous."

Similar packages addressed to Clinton and Obama were intercepted on their way to Clinton's New York home, where she lives with former President Bill Clinton, and to Washington, where Obama lives with his wife, Michelle Obama. The Secret Service said neither package reached its intended recipient.

Other packages were sent to frequent Trump critics Waters, D-Calif., and former Obama Attorney General Eric Holder. His ended up at the Sunrise, Florida, office of Wasserman Schultz, who was listed as the return address.

A police bomb squad removed the package addressed to Brennan on Wednesday from CNN's New York office, which was evacuated.