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The first rule of fight club? Do not talk about it.

But some students at a Northern California high school seemed to forget about that rule when they shared videos of what looks to be an organized fighting ring on campus.

At least three clips posted on social media appear to show students fighting in a locker room at Nevada Union High School, said Principal Dan Frisella.

The clip above shows students fighting each other in boxing gloves while others watch.

“It was surprising and it was concerning,” Frisella told Fox 40.

The school district is now investigating how long this has been going on and who knows about it.

The school’s baseball team, along with other students, is said to be involved.

According to CBS News, “the district superintendent said she only learned about the fight club recently, but the fights may have been going on for years.”

The network reported:

“Current and former students told CBS station KOVR the fights have been held for more than a decade, with kids getting knocked out, receiving bloody noses and black eyes and even going home with concussions.”

Students involved could face suspension and possibly other penalties.

Watch more, above.

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