An Islamic school in Northern Virginia has revised its religious textbooks in an apparently unsuccessful move aimed at ending longtime accusations that the school promotes hatred and intolerance.

The Islamic Saudi Academy, which teaches nearly 900 students in grades K-12 at its campus outside Washington, D.C., developed new Islamic studies textbooks for all grades after a 2008 congressional report called portions of the previous editions troubling.

The school deleted from its texts some of the most contentious passages, including references to Jihad, killing infidels and hatred of Jews and Christians.

But critics say the books are still "toxic" and contain more subtle references, such as criticism of secular forms of government.

Ali Al-Ahmed, director of the Gulf Institute, which has been pressing the school to make revision since 2004, told FOX News that the textbooks characterize secular governments as "committing unbelief and allowing us to wage war against them."

"So you're teaching American students -- implanting the seeds of insurgency in these people -- and this is very dangerous," Al-Ahmed said.

He added that the textbooks teach girls that they should not aspire to be judges or political leaders and when a girl gets married, she must ask her husband if she wants to leave the house.

The school has stood by its latest revision.

"We know our students' needs," school director Abdul Rahma said. "We believe these books match their needs."

The U.S. Commission on International Religious Freedom says it wants to look at the books but the Saudi government, which funds the academy, won't give the panel a copy.

"We can't figure out what the Saudi government has to hide and why they continually keep these secrets," said Felice Gaer, chairwoman of the commission.

Gaer's panel released a 2008 report commissioned by the U.S. Congress which stated the school's earlier textbooks contained several troubling passages, including one that claims it is permissible for Muslims to kill adulterers and converts from Islam, and another that claims "the Jews conspired against Islam and its people."

Gaer said the State Department should translate the textbooks and determine whether they encourage violence, which would be against the law.

The school has come under fire before.

Founded in 1984, it drew national attention after the Sept. 11, 2001, attacks, which turned the focus onto the Saudi educational system after 15 of the 19 hijackers were of Saudi origin.

In December 2001, former ISA students Mohammed El-Yacoubi and Mohammed Osman Idris were denied entry into Israel when authorities there found El-Yacoubi carrying what the FBI believed was a suicide note linked to a planned martyrdom operation in Israel.

In 2005, a former ISA valedictorian, Ahmed Omar Abu Ali, was convicted in federal court of joining Al Qaeda while attending college in Saudi Arabia and plotting to assassinate President George W. Bush.

Last year, the school's then-director Abdalla al-Shabnan was convicted of failing to report a suspected case of child sex abuse.

The school had hired two outside academics with backgrounds in Middle East studies to review the textbooks. The two, Eleanor Doumato, a visiting fellow in international studies at Brown University, and Gregory Starrett, an anthropology professor at UNC-Charlotte, reported back favorably.

"These books do not contain inflammatory material, nor do they encourage students to exhibit intolerance or violence toward others," the two wrote in a letter to the academy.

But Al-Ahmed said the Gulf Institute is putting together a detailed report on these textbooks that he says will show that the school "has been deceiving' the American people on its real intention.

FOX News' Molly Henneberg and The Associated Press contributed to this report.