A substitute teacher in Texas is under investigation after she allegedly turned her classroom into a cage match and encouraged students as young as 12 to fight each other.

Natally Garcia, 24, was immediately fired after the incident at Kimbrough Middle School in Mesquite on Wednesday, the school district told KXAS-TV.

Shocking footage from inside the classroom shows desks pushed into a circle to create a “fight ring” while 12- and 13-year-old students duke it out, leaving some battered and bloody.

“Her actions are appalling and intolerable,” the Mesquite ISD said in a statement.

The school district also said Garcia outlined rules for the children to follow and told one to keep watch at the door while the fights occurred.

In the video, Garcia can be heard telling her class that she “does not want this on record” and threatening to confiscate cellphones if students had them out.

The clip shows at least four students fighting each and a timer can be heard going off at different points during the melees, Garcia shouting “30 seconds” before one fight began.

“I was devastated. I was like, I couldn’t watch the full video,” Beatriz Martinez, whose daughter recorded the incident, said. “I had to stop it multiple times because I didn’t think it was real. I was like, this must be a prank. This is not real.“

“There’s no explanation, she just wanted those kids to fight,” she added.

Martinez said Garcia taught her daughter’s class at least twice before and there had been no previous incidents.

She said her daughter had been pushed to fight three girls during the makeshift fight club, but the class concluded before that could happen.

“She was really saved by the bell,” Martinez said.

Mesquite ISD said Garcia had been hired on March 6, but she was fired after the incident and is not eligible to be rehired.

“Our investigation revealed that this substitute teacher encouraged students to fight each other during class, outlined rules for the students to follow and even instructed a student to monitor the classroom door while the fights took place,” the school district said.

“As educators, our hearts are heavy knowing that an individual entrusted with the supervision and care of our students could behave in this manner, and we share the disgust that the families of students in this class must feel,” the district added.