CLAYTON (CBS SF) — Some parents at an elementary school in the Contra Costa County have stopped sending their kids to class because they say the school has become dangerous because of a third grader.

Students and parents at Mount Diablo Elementary School in Clayton say one child is terrorizing the entire school.

“He punched someone in the stomach, and then he ran into the bathroom and locked the door. And then he threw the trash can at the bathroom door,” student Chantelle Crankson said.

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Chantelle says the boy even threw rocks, and other things at students and teachers.

“It makes me really scared because sometimes he runs around the whole school, and if he sees you looking at him, he’ll run up and scream in your face,” Chantelle said.

Parents say the disruptive and violent behavior has forced the principal to lock down all classrooms on campus a few times, most recently on Monday.

“She told us to get inside and lock your door,” third grader Lily said.

Parent Tara Lesage pulled Lily out of school the last two days; about 30 other parents have done the same.

“Just want the board to listen, the district to listen, to just make a healthy and safe learning environment for everyone,” Lesage said.

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Many parents complain the district has done little to fix the problem, saying the school hasn’t even sent out a letter about bullying.

“I know a lot of kids are nervous about being in the classroom, and are hesitant to go to school, and that’s not an okay situation,” Parent Courtney Thearle said.

The parents say that if the district can help calm the boy down, it will fix the problem for everyone. The district declined to comment on the situation, saying they are addressing the parents’ concerns.