Three sixth-grade white boys at a Christian school in Virginia where Vice President Mike Pence’s wife works cut a black girl’s hair, calling it “nappy” and her “ugly,” the girl says.

Amari Allen, 12, told NBC Washington that she was about to go down a slide during recess at Immanuel Christian School in Springfield on Monday when one of the boys grabbed her and put his hand over her mouth. The second boy grabbed her arms, while the third cut off some of her dreadlocks.

“They said my hair was nappy and I was ugly,” she said.

The attack happened Monday, but Amari said she was afraid to tell anyone until Wednesday when a family member was doing her hair and noticed the missing locks. Amari broke down in tears as she recounted the story to the family member, she and her grandfather told the news outlet. She said the same three boys have been bullying her since the beginning of the school year.

Amari’s grandfather said he was deeply shaken by her account. “My heart just broke,” he said. “I was just paralyzed. I couldn’t get myself together.”

The family reported the alleged assault to the Fairfax County Police Department. A spokesman for the department told NBC News that officers are working with the school to investigate the incident.

Stephen Danish, the head of Immanuel, said the school has “a zero-tolerance policy for any kind of bullying or abuse.

“We take seriously the emotional and physical well-being of all our students,” he said in a statement. “We are deeply disturbed by the allegations being made, and are in communication with the family of the alleged victim to gather information and provide whatever support we can.”

He said school officials had also reached out to police. He later added that all four students involved in the incident have “stepped away” from school during the police investigation.

Vice President Mike Pence’s wife, Karen, worked as an art teacher at Immanuel for 12 years, and started teaching there again in January. A school spokeswoman confirmed Friday that Pence was still working there part-time.

When Pence returned to Immanuel, it emerged that the school bars employees from engaging in or condoning “homosexual or lesbian sexual activity” and “transgender identity.”

At the time, Pence’s communications director said, “It’s absurd that her decision to teach art to children at a Christian school, and the school’s religious beliefs, are under attack.”

Karen Pence’s office did not immediately respond to a request for comment on the alleged incident at the school.