The FBI has said that at least five of the packages bore a return address for the Florida office of U.S. Representative Debbie Wasserman Schultz, who formerly chaired the Democratic National Committee.
Even so, authorities are treating them as "live devices" not "hoax devices", New York City Police Commissioner James O'Neill said Thursday.
Two law enforcement officials said a package closely resembling parcels sent to critics of President Donald Trump was found at the postal facility in Manhattan.
Democratic party, CNN and many other media outlets said that Trump's rhetoric and also his anti-press statement is responsible for the current divisive atmosphere in the country. Soros has called Trump's presidency "dangerous".
The arrest came on the same day law enforcement found three more devices - in Florida, New York and California - and capped off an increasingly tense five-day stretch in which at least one explosive device was found each day, putting officials and potential targets on high alert.
Meanwhile, a local police bomb squad and canine units joined federal investigators on Thursday to examine a sprawling U.S. mail distribution center at Opa-Locka, northwest of Miami, Miami-Dade County police said.
Details about how authorities ultimately found the two Biden packages on Thursday morning in DE weren't immediately available.
Wray declined to say whether the devices could have detonated, saying that investigators are "still trying to determine whether or not they were functional".
2 girls arrested for plot to kill classmates
Afterwards, the girls would leave the body parts at the school's entrance before killing themselves, they said. When the girl's mother called the school, the assistant principal found the students hiding in the bathroom.
The package sent to CNN was discovered at a mail facility in Manhattan. On Friday, postal officials intercepted the package for Clapper, a CNN contributor, before it could reach the CNN offices, where it was addressed, according to the network.
The parcels each consisted of a manila envelope with a bubble-wrap interior containing "potentially destructive devices", the Federal Bureau of Investigation said.
All of the packages listed the Florida office of Rep.
"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. The president alluded to the shooting previous year at a mostly Republican baseball practice outside Washington, D.C., in which Rep. Steve Scalise, R-La., was badly wounded. A Justice official told CNN that Sessions canceled a trip to Louisiana scheduled for Friday to ensure that all resources, such as his plane and personnel required for his travel, would be available for the ongoing investigation.
The bombs have heightened tensions during the closing days of a highly contentious campaign ahead of the November 6 elections in which Democrats are battling to seize control of Congress now held by Trump's Republican Party. Wasserman Schultz teared up as she described the bravery of her staff in dealing with the bomb addressed to Holder that was delivered to the office.
Similar packages addressed to Hillary Clinton and former President Barack Obama were intercepted on their way to Chappaqua, New York, where Clinton lives with former President Bill Clinton and to Washington, where Obama lives with his wife, Michelle.
Brennan replied Trump should stop blaming others and should "Look in the mirror".
The discoveries - making 12 so far - further spurred a coast-to-coast investigation, as officials scrambled to locate a culprit and possible motive amid questions about whether new packages were being sent or simply surfacing after a period in mail system. Records show he was born in NY and according to an online resume he attended college in North Carolina.
The bombs seized on Wednesday were about six inches 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.
The suspected explosives De Niro received was the eighth one discovered. It was found at a New York City postal facility and was similar to the other packages, the official added.