A 12-year-old African-American girl has accused three white classmates of pinning her down and cutting off her dreadlocks with scissors.

Amari Allen says the assault happened during break time at her private school in Springfield, Virginia, on Monday.

She alleges that the boys held her down on a slide and called her hair "ugly" and "nappy" and cut some off.

The alleged attack took place at the Immanuel Christian School, where the US Vice-President's wife teaches.

The school and local police both confirmed they were investigating the incident.

"The boys came up to me and they ambushed me sort of, like caged me in," Ms Allen told local media.

"And so they put their hands over my mouth. They put my hands behind my back and they started cutting my hair and told me that I was ugly."

"They like took my lunch and ate it in front of me and told me I didn't deserve it, that I could just starve and stuff like that," Ms Allen added.

“We have a rich tradition in America of Christian education, and frankly religious education broadly defined,” he continued. “We'll let the other critics roll off our back, but this criticism of Christian education in America should stop.”