Law enforcement officials have not said whether the van in question was connected to the person taken into custody in Florida in connection with the mail bombs sent to prominent critics of President Donald Trump.
One of the parcels found on Friday was addressed to Democratic Party senator Cory Booker in Florida, with the Federal Bureau of Investigation saying it was similar in appearance to the others that had been seized.
Police in NY said they were responding to a suspicious package in midtown Manhattan, just blocks from where one of the explosive devices was found earlier this week at CNN's offices in the Time Warner Center.
Investigators are nevertheless treating the devices as "live" explosives, not a hoax, said James O'Neill, police commissioner of New York City, where two of the parcels have surfaced.
He said investigators were able to trace Sayoc after finding a fingerprint on an envelope containing a bomb sent to Rep. Maxine Waters, D-Calif., and that DNA found on two of the devices was a possible match to a sample previously taken from Sayoc during an earlier arrest in Florida. Cory Booker (D-N.J.) and former Director of National Intelligence James Clapper.
The episode sparked an outcry from Trump's critics, who tried to pin the blame for the letter bombs on the president, claiming inflammatory rhetoric against Democrats and the press was creating a climate for politically motivated violence.
The list of bombing targets spread from New York, Delaware and Washington DC to Florida and California.
Federal authorities have arrested Cesar Sayoc of Florida in connection with the suspected explosive packages discovered this week, law enforcement sources say. Other packages sent to prominent Democrats on Wednesday also listed a return address for Wasserman Schultz's South Florida office.
The first in the series of explosive devices was found Monday in a mailbox outside the NY home of billionaire philanthropist George Soros, a major donor to Democratic candidates.
Trump, in a tweet Thursday, blamed the "Mainstream Media" for the anger in society.
"It remains possible that other packages have been sent", he said at a press briefing in NY, stating that some of the packages had been sent by mail.
Video: Authorities continue to investigate additional suspicious packages containing explosives that seem to target prominent liberal figures and Democratic politicians the week of October 22.
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All packages were either intercepted or discovered; none have detonated and no one has been hurt.
The packages heightened nationwide tensions and fears two weeks before major congressional midterm elections.
"There's something more powerful than bombs, and that's your vote", the 75-year-old Hollywood star said.
Details suggested a pattern - that the items were packaged in manila envelopes, addressed to prominent Trump critics and carried USA postage stamps.
He added that the packages would "not silence the Trump administration's critics". On Thursday at the White House, press secretary Sarah Huckabee Sanders complained that 90% of coverage of the president is negative, while calling it "ridiculous" to suggest that Trump's rhetoric was in some way responsible for the mailing of the threatening packages.
The stickers included images of American flags, and what appeared to be logos of the Republican National Committee and CNN, though the writing surrounding those images was unclear. It was addressed to CNN's NY office, just as one had been earlier in the week that former CIA Director John Brennan's name on it. "It has gotten so bad and hateful that it is beyond description".
President Donald Trump says he will "address the investigation into the bomb packages" shortly.
The US president responded by tweeting: "Robert De Niro, a very Low IQ individual, has received too many shots to the head by real boxers in movies".
A police spokesman said the parcel "was similar to explosive packages that had been publicised".
In response to the events, Trump decried political violence but also joked about moving to more polite speeches.
"Let's get along", he said at a Wisconsin rally on Wednesday night.
"Did you see your face on that van, sir?"