(CNN) The principal of a New Jersey middle school was leading a graduation rehearsal Friday when student stabbed him in the chest multiple times, police said.

The student, a 14-year-old boy who was not identified, ran across the gym at Union School in Rutherford, New Jersey, and attacked Principal Kurt Schweitzer with a folding knife, according to the city's police department.

After the stabbing, the student "turned around, dropped the knife and put his hands up in the air," police said.

Schweitzer and the student were both treated for injuries that were not life threatening.

"No one is in danger, no students were hurt," the police department wrote on their Facebook page.

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