Graduation from a madrasa in Rawalpindi, Pakistan, requires memorization of 6,666 verses from the Quran (search), the Muslim holy book, and some say these strict teachings are fanning the flames of terrorism.

There are anywhere between 10,000 and 70,000 such schools in Pakistan, most funded by private donations — much of that money coming from outside the country.

Supporters say the rote memorization sharpens the minds of future Islamic scholars. And without madrasas, they say, these children would get no education at all.

There is no furniture here; no pencils, computers or magazines. Science, math and English aren't taught ... a world with its own rules behind a wire cage, rules made by the mullahs, not regulated by the state.

It is a world where Usama bin Laden (search) is openly proclaimed to be a hero by the men in charge.

"It is not only the madrasas," said Mullah Abdul Rasheed Ghazi. "It is the whole of Pakistan. If you have a poll they would say that Usama bin Laden is our hero, and that Bush is our enemy."

Calls for reform have come not just from the United States, but also from neighboring Afghanistan, whose leaders blame the madrasas for turning out Taliban extremists.

Islamic parties in Pakistan have rejected attempts to broaden curriculum as American interference. Most clerics have refused offers of financial aid from the Pakistani government to register their schools or to open up a one-book world.

Click here to watch a report by Fox News Channel's Steve Harrigan.