Parents in a Pennsylvania school district are turning 50 shades of red over word search puzzles given to their middle school students.

The students were given puzzles based on the erotic novel and movie "Fifty Shades of Grey." The puzzles contained terms including "spanking," ''submissive," ''leather cuffs" and "bondage."

Middle school students are about 11 to 13 years old.

Officials in the school district say they can't say who passed out the puzzles or how many students received one because they just learned about it Monday.

The issue became public when parents complained at Tuesday night's school board meeting.

Superintendent Leanne Spazak said the incident was under investigation.