As the Islamic State tightens its rule on Mosul, Iraq’s second largest city, the militant group has begun to turn its eyes on education, casting a shadow over the start of the school year.

Islamic State leaders want students, staff members and administrators segregated by gender. They have imposed a dress code that requires men to wear wide-legged pants and women to cover up their faces and hair. They have cancelled classes in art, music, history, geography, civics, philosophy, sociology, psychology and Christian religion. They have asked mathematics teachers to remove any questions that refer to moneylending, democracy and elections. Biology teachers can’t refer to evolution. Arabic classes are forbidden from teaching any “polytheist” poems.

The militant group’s announcement that the new school year would resume on September 9 created a whole new set of worries for residents already coping with growing violence and poverty. Most disobeyed.

“The majority of Mosul residents refused to send their children to school,” says Abu Mohammed, 27, of Mosul. “The classes should have resumed but no schools were open and nobody attended.”

Since the Islamic State took over Mosul, the group’s leaders have imposed their radical interpretation of Islamic law, dictating everything from how to dress to who can live in what homes.

In an education manifesto, the Islamic State called for attempts to “decrease ignorance, spread religious sciences, resist corrupt sciences and curricula and replace them with righteous Islamic curricula.”

Specifically, the Islamic State decreed that all primary and secondary students would graduate from the academic year 2013-2014 regardless of their exam results or other criteria except for those in the last grade of high school, when Iraqi students can apply for college or university.

The Islamic State wants anything praising the concept of homeland and nation—essentially the Iraqi government—out of textbooks and classrooms. Those concepts are supposed to be replaced the new idea of the Islamic State’s caliphate or religious government. The Islamic State leaders are removing reverences in religious curricula to the Shiite sect and other elements they consider “infidels.” They cancelled athletics classes.

They asked chemistry and physics teachers to remind students that they must follow the laws of Allah. Pictures and illustrations deemed un-Islamic in curricula must be removed.

The situation is not much different in Syria’s eastern province of Raqqa, which is mostly under the Islamic State’s control. The Islamic State announced a compulsory course for all teachers to learn the militants’ view of the basics of Islamic law. Those who don’t attend will be prevented from teaching. Teachers have had to blur all images that do not agree with the Islamic law, stop teaching the concept of patriotism and change references to the government from the Syrian Arab Republic to the Islamic State.

In Iraq, universities are also seeing sweeping changes.

“They have canceled some faculties and changed the curricula of others including the Islamic studies at Imam Adham College, says Ali, 32, a lecturer at University of Mosul. Sufi and Shiite clerics are forbidden from giving Koranic lessons at mosques.

Some locals say the Islamic State’s decision to begin the academic year is a display of power over the large swathes of territory they conquered in Iraq and Syria and a way to spread their extremist ideology.

“It is recruitment of children, nothing more—they want to show the world that they are ruling this city and that they are not afraid of the global alliance against them,” says Um Shams, 45, a mother of two, who lives in Mosul. “But with the first bombardment, there will be no student there.”

Local residents are resisting. “I assure you, nobody among the Mosul people will send their sons to schools where their minds might be poisoned with the extremists’ ideology,” says Abu Mohammed.

The students worry that going to school will not lead anywhere. “Students are afraid, first of all that nobody will recognize the certificate they will get under Islamic State rule,” says Um Shams. “My 18-year-old son refuses to go to take exams which nobody will recognize.”

Teachers and administrators are unsure what to do. The Islamic State “has distributed a document determining the educational process according to its rules with lots of details left out,” says a Mosul headmaster who asked not to be named. “They asked teachers and headmasters to attend their schools without any mention of their salaries, for example.”

Since June, the Islamic State has imposed some salary cuts, a hardship where the majority of residents are government workers. Many workers feel lucky to get paid at all. Some teachers received their salaries in July and August, but are unclear if they will be paid in September.

Many school officials say they don’t know what to do in absence of any clear official authority. “The staff are caught between the hammer of the Islamic State and the anvil of the Iraqi government,” says Abu Mohammed. The Islamic State has said that teachers must attend schools or lose their salaries. On the other hand, the Iraqi government has said that any teachers who report to work in the Nineveh governorate—of which Mosul is a part—will not get their salaries anymore.

September 9, the official school year opening day, came and went, with a skeletal staff and few students.

“Schools opened but the staff signed their attendance sheets and left,” says Ali, the lecturer at the University of Mosul.

Meanwhile, students are afraid to go to school. Islamic State guards at the school doors check for “un-Islamic” clothing, search the students’ mobile phones for songs and ask female teachers to cover their faces and put on gloves, says Um Shams, who adds that she has even bigger concerns.

“This is unbearable, she says. “I am afraid they will force students to watch public executions and punishment as they are doing now in public places.”

This concern is borne out by the Islamic State’s own educational manifesto. In it, they ask academics and teachers from within Mosul as well as outside the city to assist the militants and quote a verse from the Koran exhorting the faithful to “terrify the enemy of Allah.”

The manifesto also says that military training will be mandatory as “the core of religion consists of the guidance of the Koran and victory with swords.”

Some parents say the children don’t realize fully what is going on.

“Some of my son’s friends went to school and Islamic State members told them to wear wide pants, to fully button their shirts,” says Um Shams. “They make fun of their female teachers covering their faces but they don’t realize how dire our situation is.”

Gilgamesh Nabeel reported from Istanbul. Rasha Faek contributed to this article from Amman, Jordan.