The incident was part of an assignment dealing with the Reconstruction period, the school district's superintendent said, who called the impact "harmful."

DOVER, N.H. (AP) — The teacher for a class in New Hampshire in which students were videotaped singing about the Ku Klux Klan to the tune of “Jingle Bells” has been placed on paid administrative leave.

Dover Superintendent William Harbron told Foster’s Daily Democrat Tuesday that putting John Carver on leave will allow school officials to fully investigate what happened.

Cellphone footage surfaced over the weekend of the students singing, “KKK, KKK, Let’s kill all the blacks,” in class at Dover High School.

Harbron said in a letter to the school community Monday the incident was part of a class assignment about the Reconstruction period in American history.

Carver has not responded to requests for comment.