The FBI says it stopped a major terror plot in October that was set to unfold in Michigan ahead of Halloween weekend, preventing what officials described as an attack that could have killed large numbers of Americans, as reported by Fox News.

The operation also led agents to what they say is a global terror network, resulting in arrests in the United States and overseas.

FBI Director Kash Patel, Deputy Director Dan Bongino, and a senior counterterrorism agent spoke Thursday with Fox News Digital about the case and the coordinated effort behind the arrests in Michigan, New Jersey, and Seattle. Officials said the arrests were among the most significant in the counterterrorism program in recent years.

“The arrests that happened in Detroit, Newark, and Seattle represent one of the most deadly plots faced by the FBI in recent memory,” the agent told Fox News Digital.

“Those eight arrests, and ones that have happened around the world, are some of the most impactful arrests that have happened in the counterterrorism program in recent years.”

Two men from Dearborn, Michigan — Mohamed Ali and Majed Mahmoud — have been charged in federal court.

Prosecutors say the charges include transferring firearms and ammunition, conspiring or attempting to do so knowing they would be used to commit and support terrorism, and providing material support to ISIS.

The FBI says five individuals were involved in the planned attack, including one minor.

Patel said investigators acted immediately against the individuals deemed to be the “overt actors,” while continuing surveillance of additional suspects.

“We arrested the people who were the overt actors immediately, while constantly surveilling the people in New Jersey and Seattle,” Patel said. “We arrested them in a coordinated fashion thereafter to take down the entire network.”

Patel also responded to criticism about the FBI’s timeline, saying that waiting longer could have risked lives. “If we were to do this the way the media wanted us to do it, we would have waited for them to kill Americans, and then arrest them,” he said.

The senior agent said the arrests revealed a broader network that extended beyond the United States.

“If we hadn’t moved, we would not have fleshed out the entire network that we now know spans the entire globe,” the agent said, adding that additional arrests overseas were directly tied to the same plot.

He declined to provide further details due to ongoing prosecutions in the U.S. and Europe.

Bongino said intelligence suggested that the consequences of inaction would have been severe. “People would have died. A lot of them. That’s a fact. A lot of people would have died,” he told Fox News Digital. “And their work stopped it.”

According to court documents, FBI agents executed search warrants in October on the homes of Ali and Mahmoud and a storage unit the men allegedly shared.

Investigators seized semiautomatic rifles, a shotgun, handguns, tactical gear and more than 1,600 rounds of 5.56 mm ammunition. Surveillance video recovered by agents also allegedly showed Ali and others at a Michigan gun range practicing shooting.

An FBI affidavit states the alleged conspirators drew inspiration from the 2016 Pulse nightclub shooting, as well as the 2015 coordinated terror attacks in Paris that killed 137 people and injured more than 400.

Investigators say the suspects in Michigan sought advice from the father of a local “Islamic extremist ideologue,” allegedly seeking religious approval for the attack.

They also allegedly discussed choosing a date that would be celebrated by future radical Islamic terrorists.