A public school system in Maryland is being sued for promoting Islam over other religions.

The lawsuit was filed in federal court Wednesday on behalf of a former Marine and his wife who fought back at their daughter’s high school for forcing students to complete assignments that endorsed Islam.

The Thomas More Law Center filed the civil rights complaint in the U.S. District Court for the District of Maryland, accusing leaders at the Charles County Public Schools of violating the plaintiffs’ constitutional rights.

John Kevin Wood, who served eight years in the Marine Corps, and his wife Melissa objected when they discovered that their daughter’s World History class at La Plata High School was circulating assignments that amounted to Islamic propaganda.

Their daughter and her fellow students were instructed to write out the Islamic creed "Shahada," which says, "There is no god but Allah, and Muhammad is the messenger of Allah." When recited by non-Muslims, the creed amounts to conversion to Islam.

Students were also required to memorize and recite the Five Pillars of Islam and were subjected to disparaging teachings about Christianity.

"Most Muslims’ faith is stronger than the average Christian," one worksheet read.

The class also spent one day covering Christianity, while teachers devoted two weeks to instructing about Islam.

Upon learning of the lessons prioritizing Islam, Wood, who is Christian, contacted the school and demanded alternative assignments for his daughter. The school refused to allow his daughter to opt out of the assignments and threatened her with failing grades if they were not completed. She elected not to complete the worksheets.

The complaint filed Wednesday charges that the school discriminated against Wood’s daughter "by removing her from the academic environment of her World History class, relegating her to the student library, and issuing her failing grades on assignments because [she] refused to deny and insult her Christian beliefs."

Following Wood’s complaints, the school principal also banned him from entering school grounds.

The lawsuit was filed against the Charles County Public Schools, the Board of Education, and the principal and vice principal of La Plata High School. It seeks a declaration from the defendants that they violated the plaintiffs’ constitutional rights, in addition to a temporary and permanent injunction barring them from promoting Islam over other religions and from banning Wood from school grounds.

In announcing the complaint, the president and chief counsel of the Thomas More Law Center warned that schools across the nation are forcing such "Islamic indoctrination."

"Parents must be ever vigilant to the Islamic indoctrination of their children under the guise of teaching history and multiculturalism. This is happening in public schools across the country. And they must take action to stop it," Richard Thompson, the law firm’s president, said in a statement.