At least two city Islamic schools where children spend their days memorizing Koranic verses are coming under scrutiny from the city’s education department, which is assessing whether the religious schools violate the law by focusing the school day exclusively on rote religious texts instead of subjects like arithmetic, science, and civics.

“We are in the process of getting in touch with them to see what’s going on there,” the general counsel for the city Department of Education, Michael Best, said last week. “If there are concerns, we’ll have to address them pursuant to the state guidelines.”

Mr. Best called such inquiries “rare.”

“If a school doesn’t inform us or announce they’re around, then we may not know about them,” he said.

New York State has at least 1,125 Christian schools, 370 Jewish schools, and 21 Islamic schools, according to state education statistics. Like their Jewish and Christian counterparts, the majority of the Islamic schools have traditional reading, writing, and arithmetic curricula; the intensive Koranic programs are unusual.

After initially telling The New York Sun that private schools are a matter for Albany, city education officials said later that they had “knowledge” of the centers and that they would inquire whether they follow state laws that require standard subjects like music, U.S. history, physical education, and geography, to be taught to prepare students “for their place in society,” in the words of state guidelines for nonpublic schools.

At the schools being examined by the city Department of Education — including the Jamaica Muslim Center and the Muslim Center of New York in Flushing — a child can study to become a “hafiz,” a religious honorific given to a person who has committed all the verses in the Muslim holy book to memory.

City education officials say the investigation was triggered by a feature story about the schools in mid-August in the New York Times.

Even at the Flushing Muslim center, most of the students receive standard education, with the all-day Koranic studies students being in the minority.

One of the three supervisors of the Flushing hafiz program, Mohammad Sherwani, said school officials are considering supplementary tutoring instruction starting around the time of Ramadan, the Muslim holy month that begins in late September. Another option under deliberation would allow parents to arrange such tutoring.

“So many things going on that if I give you the information, it would be hodgepodge,” Mr. Sherwani told the Sun.

Mr. Sherwani said he didn’t know whether the school has been in touch with city education officials, although it is possible the center’s board of directors has.

The hafiz schools are popular in South Asia, but rare in America.

“Public school officials need assurance that pupils in a new school are receiving an adequate instructional program,” according to state guidelines for nonpublic schools.

Muslim religious leaders call the hafiz honor a gateway to heaven — one of the holiest marks a Muslim can achieve — but the all-day, rote curriculum appears to come at the expense of what state law requires students to learn.

While conceding that some hafiz students enter conventional grade schools a grade or two behind after their Koran studies, the schools’ leaders defend the curriculum’s pedagogical focus on the Koran. They note that only the best students are allowed to proceed with the intensive Koranic study — roughly one in 10 students made the cut this year, the director of the Flushing center said — and almost all catch up with their peers through private tutors or extra study.

“They become so sharp, they can memorize anything,” Mr. Sherwani said.

Mr. Sherwani — whose Web site boasts that 27 boys as young as 5 are memorizing the Koran Monday to Friday between 8 a.m.and 5 p.m.— said the school has never clashed with regulators.

Parents of successful students, he said, get a receptive ear from school administrators after they produce a letter from the Islamic school officials explaining the exhaustive study program.

“Never had a problem,” he said. “We are doing this since 1999.”

This year, schools like Mr. Sherwani’s might run into a problem.

Mr. Best said there is some indication that hafiz schools might begin offering a more well-rounded education than others in the city. If the city does shutter the schools, students who continue to attend them would be considered truant, the state guidelines state.

Calls to the Jamaica Muslim Center weren’t answered.