Parents of students at ASU Preparatory Academy in Arizona are outraged because Ku Klux Klan costumes were used during a play last week.

According to ABC 15 Arizona, an adaptation of Larry Shue’s 1985 play, The Foreigner, was performed by the high school’s drama department. The two-act comedic play takes place in a lodge in rural Georgia where two Englishmen, Froggy and Charlie, are guests. Charlie is depressed because his wife is dying, and Froggy lies to the staff, saying that his friend is  a non-English speaker. The lodge guests quickly begin to share their secrets and/or scandals, including a scene in which the characters have a conflict with the KKK.

During the Klan mob scene, three students walked through the audience and onto the stage in full hooded garb, shocking the audience.

“The KKK walked into my kid’s school on Friday and I didn’t get to stop it,” one anonymous father said. “There’s no justification for it.”

He continued, “We can talk about racial prejudice, we can talk about the insensitivity, but to have our children put on the robes and assume the characters, it’s wrong.”

Shue may have intended for viewers to become uncomfortable when he decided to include the hate group in the short scene. “They are members of the Klan and must be truly cunning, obsessive, and dangerous,” wrote Rosalind Flynn for the education website, ThoughtCo.com. “While it is true that play is a comedy, Larry Shue is insistent that, at first, the audience must recoil before they can find the humor.”

ASU Preparatory Academy apologized for the incident in a statement provided to ABC 15.

“Last Friday, high school students in a drama class at ASU Preparatory Academy in downtown Phoenix staged a production of noted American playwright Larry Shue’s ‘The Foreigner,’” the statement began.

Students allegedly chose to perform the play.

The school’s statement continued: “The play portrays an image of members of Klansmen in a brief scene toward the end in which they are made fun of and driven away.

“We apologize if anyone was caught by surprise with the appearance of these characters. We are confident that a fair reading of the text of the play, and a fair interpretation of the intentions of students who performed it, reveals no endorsement of bigotry.”

The disgusted father, however, found no solace in the apology. He told the news outlet that the school should have “informed the parents” and given them “the ability to make that decision.”

The incident comes after two students from Dover High School in New Hampshire were recorded singing a racist jingle promoting the KKK and the murder of Blacks for a history assignment about the Reconstruction Era earlier this month.