CINCINNATI (AP) — A middle-school music teacher has hit a sour note with a letter warning students against having "Mohawks, Large Afros, or other outlandish" hairstyles for an upcoming school concert.

The Cincinnati Enquirer reports the letter touched off a social media firestorm over the weekend, with commenters saying it was targeting black students. Students were warned they could be sent home and forfeit their grade.

Pleasant Run Middle School apologized in a Tweet sent out Saturday. It said the letter wasn’t approved by the school administration and "does not reflect our views at all."

Messages for comment were sent Monday to the teacher and to the superintendent of the Northwest Local School District in suburban Cincinnati.

Vocal Music teacher Steven Reeve’s letter states that he’s in his first year at the school.