The FBI has paid a visit to a New Jersey high school, warning students about the online recruitment tactics of ISIS. The agency told the teens not to believe the terror group's propaganda, as it is trawling the internet to recruit vulnerable young people.

The Tuesday event, held at Bergen Arts and Science Charter School in Hackensack, NJ, was led by a senior FBI intelligence analyst who did not want to be named for security reasons.

During the talk, he told students that Islamic State (formerly ISIS/ISIL) was using social media and glossy magazines to train terrorists and make its mission seem appealing.

One of the tactics mentioned was a sophisticated recruitment video, aimed at luring young people into joining the terror group.

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The footage features a Canadian man who says that anyone can play a role in ISIS's mission, failing to mention the atrocities inflicted by the terror group. That same man later died while fighting for the group in Syria.

The event, part of the FBI's outreach campaign to warn about the terror threat, seemed to have accomplished its intended goal on some of the students.

Brayan Liz, a senior, said the talk was useful because "100 percent of students are on social media,” NorthJersey.com reported.

Another senior, Robert Harris, told CBS New York that he is “more interested than scared,” adding that he “wants to know how to find terrorists; how to stop them from doing things.”

“It definitely was eye-opening,” said high school senior Zoey Zibor. “You know, you learn that it’s in your own backyard. It’s Americans citizens wanting to join these terrorist groups.”

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The FBI analyst stressed that the talk was about ISIS as a terror group, not a religious one. Still, some students expressed frustration about the event.

"I did kind of feel offended because they're putting a bad reputation on Islam in general. That has nothing to do with Islam," said junior Safiye Taspinar.

That sentiment was shared by Glenn Katon, legal director for the civil liberties group Muslim Advocates.

He tweeted that Muslims account for only about 6 percent of extremist violence in the US, but the FBI focuses all of its anti-extremism measures on Muslims.

"The FBI keeps peddling 'radicalization' rubbish," he wrote.

The presentation was requested by the school's security director, Leo McGuire, "to educate and inform students so they don't get dragged into the recruitment tools that some of the terrorist organizations are using."

He added that students have a “part to play in count-terrorism operations.”

The FBI plans to take its message to other schools in the tri-state area.

More than 150 Americans – some of them teenagers – have traveled abroad to join ISIS, according to the FBI. The agency's intelligence analyst said that all of the bureau's 56 field offices have had cases of people being recruited to join the terror group.