An upstate New York man was arrested in the Big Apple after allegedly claiming he was traveling to attack federal agents on the same day thousands of people took to the streets to participate in the nationwide "No Kings" protests. 

David Cox, 54, was taken into custody in Brooklyn on Saturday after he claimed to have firebombs in his vehicle and planned to "fight ICE agents" at the Manhattan protest, The New York Post reported.

Cox allegedly made the threats while speaking to a bystander at an upstate gas station on Friday night, the NYPD said. 

PROTESTERS NATIONWIDE HOLD 'NO KINGS' RALLIES AMID GOVERNMENT SHUTDOWN

After Cox left, the bystander called local authorities to report the pair’s conversation. 

The next day, as 100,000 demonstrators flooded the city’s streets for a "No Kings" rally, authorities were alerted that Cox’s vehicle had crossed into Brooklyn, and he was taken into custody without incident, according to the NYPD. 

Police did not locate any firebombs or weapons inside Cox’s vehicle, The Post reported. 

WATCH: 'NO KINGS' PROTESTERS AT MASSIVE NYC RALLY REVEAL MOTIVATION FOR TAKING TO THE STREETS: 'DISGUSTING'

Cox is charged with making a terroristic threat, false report of terrorism and making a threat of mass harm, police said. 

The charges come after tens of thousands of protesters spoke out against President Donald Trump’s administration in the nationwide demonstrations, with attendees often clad in satirical costumes and carrying signs. 

Despite the large crowds descending on the Big Apple, no protest-related arrests were made, according to the NYPD. 

'NO KINGS' ORGANIZER DISCOURAGES VIOLENCE FOLLOWING COAST-TO-COAST ARRESTS

However, three people were arrested in Portland after federal authorities were forced to deploy tear gas on protesters when one rally turned violent. Additionally, 15 people were arrested at a protest outside a Broadview, Illinois, ICE facility. 

Fox News Digital was unable to immediately locate an attorney representing Cox. 

Rep. Chip Roy, R-Texas, tore into the Democratic Party during House GOP leaders' press conference on Day 20 of the government shutdown after anti-Trump protests swept the country over the weekend.

He blasted the left's embrace of the "No Kings" rallies, where millions of people across the U.S. took to city streets to protest President Donald Trump.

"This is the dying breaths of a bankrupt party, in my humble opinion, all too happy to shut down the government," Roy said during the press conference Monday.

He and House Freedom Caucus Chair Andy Harris, R-Md., joined House GOP leaders' daily shutdown press conference in a show of unity across the Republican conference.

GOVERNMENT SHUTDOWN 101: WE'VE BEEN HERE BEFORE, HERE'S WHAT HAPPENS NEXT

"No one disputes one obvious fact: It is Democrats who have chosen not to fund government. We can at least establish that truth, right? It is, in fact, the truth. And the question is, why?" Roy said.

"And you saw it on Saturday — it was basically for a political rally, a rally for cover for [Senate Minority Leader Chuck Schumer, D-N.Y.], who's in his own political battle in New York," he added in reference to Republican accusations that left-wing leaders are kowtowing to Democrats' progressive base.

He continued, "That's the truth. And the irony of this is, this ‘No Kings’ rally. What are we actually talking about? I mean, it wasn't President Trump, but Democrats who tried to make us take a shot or lose our job. It wasn't President Trump, but Democrats who were burning our cities to the ground in 2020 and attacking police officers."

Republican leaders spent last week hammering Democrats who planned to participate in Saturday's "No Kings" rallies, including Schumer.

House Speaker Mike Johnson, R-La., during his portion of the press conference, made a plea to Schumer to accept the GOP's federal funding bill now that the protests were over.

"Now that Democrats have had their protest and publicity stunts, I just pray that they come to their senses and end this shutdown and reopen the government this week. Republicans are waiting. The American people are waiting," Johnson said.

SCREAMING MATCH ERUPTS BETWEEN HAKEEM JEFFRIES, MIKE LAWLER AS GOVERNMENT SHUTDOWN CHAOS CONTINUES

The House passed a bill to keep the federal government funded at current levels through Nov. 21 — called a continuing resolution (CR) — mostly along party lines last month.

It's since failed 10 times in the Senate, with a majority of Democrats rejecting any spending deal that does not also include an extension of COVID-19 pandemic-era Obamacare subsidies that will expire at the end of this year without congressional action.

The ongoing government shutdown is now the third-longest in history.