They brought to at least 10 the number of suspicious packages intercepted by authorities this week.
Police are examining a suspicious package addressed to actor-director Robert De Niro at a building in Lower Manhattan's Tribeca neighborhood, two law enforcement sources said early Thursday.
The address, 375 Greenwich St., matches that of the Tribeca Film Center as well as De Niro's Tribeca Grill restaurant. The packages were in manila envelopes with bubble wrap interior, the Federal Bureau of Investigation said.
Law enforcement officials in the city had already been under a heightened alert, increasing police presence after several bombs were intercepted on Wednesday. FBI Public Affairs Specialist Dave Fitz told CNN agents were "responding with our law enforcement partners to a US Postal facility in DE". Trump frequently labels stories he doesn't like as "fake news".
However, authorities warn they might not have found them all yet.
U.S. authorities are searching for suspects in the sending of package bombs to high-profile Democrats in what's been called a terrorist act that's raised tensions in a nation already polarised ahead of elections in November.
Some top Democrats have called the threats a symptom of a coarsening brand of political rhetoric promoted by Trump, who also condemned the acts.
Trump's words didn't satisfy his political opponents, however.More news: Meghan's daring slit-to-the-thigh dress
The former state secretary said "we are fine" at a Florida fundraiser. Democratic House and Senate leaders Nancy Pelosi and Chuck Schumer both said that conciliatory talk sounds "hollow" coming from Trump.
Last week, Mr Trump, who joined other Republicans in accusing Democrats of encouraging "mob" tactics, heaped praise on a Montana congressional candidate who assaulted a reporter during his successful 2017 campaign.
Law enforcement officials said all the packages were similar: manila envelopes with bubble-wrap interior bearing six stamps and the return address of Wasserman Schultz. She is the former chairwoman of the Democratic National Committee who was accused by Clinton rivals of secretly helping the party's eventual presidential nominee. Debbie Wasserman Schultz, whose return address was on it.
One target of the suspicious devices, former CIA Director John Brennan, hit back at Trump on Twitter on Thursday.
The first package, which turned up on Monday, was addressed to Soros, the billionaire financier and frequent target of right-wing conspiracy theories.
President Trump addressed the suspicious packages, many of which were found throughout the day on October 24, during his speech at a campaign rally in Mosinee, Wisconsin.
"The packages were immediately identified during routine mail screening procedures as potential explosive devices and were appropriately handled as such", the Secret Service said in a statement. Officials provided no details on a possible suspect or motive.