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COVINGTON, Ky. — When students return to Covington Catholic High School on Tuesday, they will be greeted by police and protesters.

The once-obscure all-male high school located across the Ohio River from Cincinnati in Park Hills, Kentucky, became instantly infamous over the weekend when video of students — many wearing “Make America Great Again” baseball caps and appearing to jeer a Native American activist on the steps of Lincoln Memorial — went viral and sparked nationwide outrage.

Now authorities are investigating threats against some of the students at the school, Kenton County Commonwealth’s Attorney Rob Sanders told the Cincinnati Enquirer on Monday.

“We will be prepared for tomorrow," Sanders told the paper.

Sanders did not elaborate on the threats in the article and did not immediately respond to an email from NBC News for comment.

Meanwhile, the American Indian Movement Chapters of Indiana and Kentucky are planning a protest outside the school starting at 10 a.m. ET on Tuesday, the paper reported.

Lance Soto, co-chairman of the Native American group, told the paper their protest will be peaceful and condemned the threats against the school.

“I think anybody threatening school children is completely wrong, and I won’t stand for it personally,” he said. “Those people are not affiliated with us.”

Sanders and Soto spoke a day after junior Nick Sandmann, who became a lightning rod for much of the outrage after he appeared to be grinning during his videotaped face off with activist Nathan Phillips, issued a statement in which he said he had received death threats.

"I have received physical and death threats via social media, as well as hateful insults," he wrote. "One person threatened to harm me at school."

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The school's principal, Robert Rowe, said the confrontation is now being examined "by an independent third-party investigator," according to an email sent to parents obtained by NBC affiliate WLWT.

"Based upon and following an investigation, we will be taking the appropriate action regarding this matter," the email stated.

While Sandmann and his classmates have been branded as bigots and now face an investigation by the school that could result in possible expulsion, they found a defender in Rep. Thomas Massie, a Republican who represents the district.

In a series of tweets on Monday, Massie admitted he was “uncomfortable” when he first saw the video of Friday’s encounter in Washington, where the Covington Catholic High School students had been attending a Right to Life march.

But Massie said he changed his mind after viewing subsequent footage and now believes they are the victims.

“What they got was a brutal lesson in the unjust court of public opinion and social media mobs,” he tweeted. “In the context of everything that was going on (which the media hasn’t shown) the parents and mentors of these boys should be proud, not ashamed, of their kids’ behavior.”

Both Phillips and the defenders of the Catholic high school students agree that the videotaped confrontation was preceded by raunchy taunts aimed at the teens by four members of a group called the Black Hebrew Israelites.

In other video footage, the Covington Catholic students can be seen responding to the taunts with school spirit chants. And in his statement, Sandmann said admitted he led some of those chants “to counter the hateful things that were being shouted at our group.” He said their chaperones gave them the okay.

Phillips told MSNBC’s Joy Reid on Sunday that his group was also targeted for abuse by the Black Hebrew Israelites. He said that he and his group approached the teens to talk with them after witnessing their bitter back and forth with the Black Hebrew Israelites.

In the footage, Phillips is seen banging on his ceremonial drum while the students encircle him and he comes face to face with Sandmann, who like many of his classmates is wearing a MAGA hat.

But instead of listening, Phillips said some of the young men began chanting President Donald Trump's mantra “'Build the wall’ and other things that were even worse."

Phillips said that if there were chaperones, they made no attempt to intervene.

"Where were they?’ Phillips said. “How did they allow these students to come to this point after an hour of this happening? Were they with them? Were they encouraging them?"

Also, in the footage, some of the students can be seen making what appears to be making the tomahawk chop gesture and make noises that appear to mock Native American chanting.

Sandmann insisted “at no time did I hear any student chant anything other than the school spirit chants.”

“I did not witness or hear any students chant ‘build that wall’ or anything hateful or racist at any time,” he said in Sunday’s statement.

As for Phillips, Sandmann said “he locked eyes with me and approached me, coming within inches of my face.”

“He played his drum the entire time he was in my face,” Sandmann said in his statement. “I never felt like I was blocking the Native American protester. He did not make any attempt to go around me. It was clear to me that he had singled me out from a confrontation, although I’m not sure why.”

Sandmann issued no new statements on Monday.