DALLAS (KXAN) — An eighth-grade social studies assignment in Dallas came under fire after criticism over how it depicted police and their treatment of Black Americans.

The assignment, given to students at Cooper Junior High in Wylie, Texas, used political cartoons that some critics, including the National Fraternal Order of Police, say compared police officers to the Ku Klux Klan and slave owners.

The cartoon shows five similar scenes: African American men on the ground with their hands restrained behind their backs and a white man’s knee on their neck — seemingly a reference to the death of George Floyd by Minneapolis police officer Derek Chauvin.

The vice president of the FOP, Joe Gamaldi, sent a letter to Wylie Independent School District Superintendent David Vinson on Aug. 19, saying, “I cannot begin to tell you how abhorrent and disturbing this comparison is, but what is more disturbing is that no adult within your school thought better before sending this assignment to children.”

According to its instructions, the assignment aimed to serve as discussion on First Amendment rights and racial equality protests across the nation during 2020 — but Gamaldi says the assignment aimed to “indoctrinate” students.

Texas Gov. Greg Abbott took to Twitter to express his displeasure with Wylie ISD and the assignment, tweeting, “The teacher should be fired” and asking the Texas Education Agency to investigate and take action.

“It’s the opposite of what must be taught,” he said.

Wylie ISD issued a statement after pulling the assignment, saying: “We are sorry for any hurt that may have been caused through this lesson. The assignment has been removed, and students will not be expected to complete it.”

The district, which did not identify the teacher due to privacy laws, also said that the cartoons are not part of the district’s curriculum resources or documents.

The Texas Education Agency confirmed to CNN that it is investigating the assignment, saying it does not condone the use of “divisive images.”

A photo of the assignment that circulated on Facebook (CNN)

The National Coalition Against Censorship has issued a letter protesting the school’s choice to remove the assignment. The coalition says the decision could “create dangerous precedent” that educators can’t present material that may be offensive to someone. The letter is cosigned by 10 other national organizations.

The image was created by cartoonist David Fitzsimmons, from the Arizona Daily Star. Fitzsimmons has since responded to the criticism, saying:

“I’m impressed the National Fraternal Order of Police is directing its fury at an illustration revealing how our present horrors are mere echoes of our cruel past… Perhaps it requires too much moral courage, or honest clear-eyed reflection, for the National Fraternal Order of Police to funnel their fury at the few racist police officers who disgrace their oath and their badges by disproportionately murdering African Americans.”