The superintendent of the Upper Darby School District has issued an apology after a photo resurfaced Thursday of students dressed in Ku Klux Klan outfits.

In a Friday statement to the Upper Darby community, Superintendent Richard Dunlap wrote that the photo of the three Upper Darby High School students was part of a skit "intended to identify and highlight the atrocities of the Ku Klux Klan."

The photo resurfaced on social media Thursday evening. In it, the students are standing next to each other, dressed in white shirts with the letter "K" on them. Their faces are covered by white Klan-style cone hats.

The three students appear to be female.

Dunlap wrote that during the 2014-15 school year, "a project was assigned in an Upper Darby High School history class with the intention of illustrating the historical impact of the 1920s."

"There were skits associated with this project, and a photo of a skit intended to identify and highlight the atrocities of the Ku Klux Klan circulated on social media [Thursday] evening," Dunlap wrote.

He added: "The photo has offended many in the community, and the Upper Darby School District is deeply sorry for this. Though there was no intention to harm or offend anyone, we recognize that the project was in poor judgment and an inappropriate activity."

NBC10 reported that the photo first surfaced on Twitter in August.

Dunlap noted that the Upper Darby School District staff, board and administration in Delaware County have been undergoing diversity training and said a plan to address diversity will also be implemented for students as well.

"The Upper Darby School District truly regrets this incident and appreciates the support and cooperation of our community as we attempt to use this as a teachable moment regarding cultural, historical, and racial understanding," he wrote.

Staff writer Rob Tornoe contributed to this article.