Parents in a Monessen, Pennsylvania are irate at school officials after Fifty Shades of Grey-themed word search puzzles were given to their middle school children.

In the latest round of controversy regarding the sexually explicit series, several teenaged students were reportedly given word puzzles that included the terms “spanking,” ”submissive,” ”leather cuffs,” and “bondage,” among other words, which are reportedly more explicit.

After catching wind of the incident, parents lodged their complaints to district administrators at a school board meeting on Tuesday evening.

One parent, James Carter, said he took issue with the school’s principal at the meeting. Carter told the local ABC affiliate he made an attempt to question the principal and another administrator, but they refused to discuss the origin of the puzzle after he attempted to record their conversation.

“I asked my son who passed it out, and he said the teacher passed it out,” Carter told WTAE. “I don’t think this is what they should be doing in the 8th grade level.”

While nobody seems to know where the puzzles originated from, one school official, Roberta Bergstedt, has called the events a “mistake.”

“It was a huge but unintentional error and collected from the five students involved as soon as it was realized,” Bergstedt wrote in an email to the AP, according to ABC News. “Unfortunately, one copy was taken by a student who then posted it on social media.”

“We just learned of this issue yesterday,” solicitor John Toohey said. “An investigation will occur.”

District officials reportedly refused to comment on whether any teachers or staff will face discipline.

Fifty Shades of Grey is scheduled for release on Feb. 13.