NASHVILLE, Tenn. (CBS/AP) — A Nashville teen has been arrested on a state terrorism charge after being accused of threatening schools in Massachusetts and three other states.

Authorities say the joint investigation by police and the FBI led them to the student, who is accused of being responsible for multiple emails and telephone calls threatening violence in schools in Tennessee, Massachusetts, Pennsylvania and Virginia.

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The FBI says the Massachusetts schools involved are Brockton High School, Whitman-Hanson Regional High School and Cardinal Spellman High School.

Part of some of the emails stated: “… since I’m such a nice person I decided to take the time to inform you before the destruction of the school takes place.”

In some of the emails, he pointed out school administrators by name.

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The teen allegedly sent five emails to Brockton High School, some of which read, “We plan to kill as many people as we can… Some students will even have a hydrogen bomb in their backpack, some will have shotguns and assault rifles. We will have three people in the woods around the school scouting for targets.”

The young man also allegedly sent 21 emails to Cardinal Spellman, which read, “Can you imagine the blood of students and teachers filling up the hallways? Brain matter splattered everywhere? Who knows? There might even be a bomb aboard a bus.”

Police were so concerned about one of those threats Thursday that they closed a high school in Nashville and wouldn’t clear it to open until the bomb squad and K-9s swept the campus. Authorities did not describe the nature of the threats.

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The student has not been identified and police have not given his age. Police would only say he lives in south Nashville and attends an alternative school.

Details of the teen were kept so secret that a spokeswoman for Metro Nashville Public Schools said police had not even told them the identity of the student that had been taken into custody Thursday evening.

“There is a definitive impact on draining public safety resources when you have bomb threats or threats of violence to schools,” said FBI Boston Assistant Special Agent in Charge Kieran Ramsey. “We are not going to stand idly by.”

He was expected to face federal charges later Friday and appear before a magistrate judge at a hearing closed to the public and the media.

Ten email messages threatening violence were made to Nashville schools between March 16 and April 16, police said.

On Thursday, Nashville police said, the threats against Antioch High School were so specific that Antioch High School officials dismissed classes at 9:45 a.m. and told parents not to drive to the school to pick up their kids. Authorities did not reveal the details of the threat.

Police and the FBI have been investigating the threats for more than a month, which proved difficult because the teen was able to mask his online identity, authorities said.

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