TEHRAN, Iran (AP) – President Ahmadinejad claimed to be delighted when reformist students disrupted his visit to their elite university in December, burning his portrait and shouting “Death to the dictator!”

It showed the world that Iranians can protest “with an absolute, total freedom,” the hard-line president wrote on his Web site.

But at least eight of Amir Kabir University’s leading reformists have been arrested since May, according to their lawyers and activists inside and outside Iran.

They are among hundreds rounded up in recent months in a nationwide crackdown on those accused of threatening the Iranian system.

Two years after Mr. Ahmadinejad’s election, the “Tehran Spring” of his moderate predecessor, Mohammad Khatami, is a fading memory. A deep chill has settled over those pushing for change inside the Islamic Republic.

Some dissenters blame the crackdown on the regime’s fear of an American effort to undermine it as tensions over Iran’s nuclear program intensify. Others say the intent is simply to contain discontent fueled by a faltering economy.

Teachers, feminists, union leaders, journalists, students and at least four Iranian-Americans have been arrested over roughly the last six months.

Most have been freed after spending days, week or months behind bars. But many of their cases remain open in Iran’s revolutionary courts, a parallel justice system that operates with few of the protections available in civilian courts, lawyers and activists said.

“The new government has increased pressures on the nation – students, laborers, intellectuals,” said Ebrahim Yazdi, foreign minister after Ayatollah Ruhollah Khomeini’s 1979 revolution and now leader of the banned but tolerated Freedom Movement of Iran.

“When laborers stage protest rallies, the government, instead of talking to them, takes them to jail. Women are jailed just for collecting signatures in support of women’s rights,” he said in an interview with The Associated Press.

Restrictions in Iran are far from absolute. Iranians criticize the government in public, and ignore a wide array of social regulations at home. Defenders of the system point out that is more open than in many nations in the region, including some of America’s allies. And some restrictions have loosened in recent months: two reform-oriented newspaper have been granted permission to publish again.

Iranian officials say the judiciary is simply prosecuting crimes. “Thank God, in Iran the rule of law prevails and the judiciary of the Islamic Republic is an independent branch,” Ahmadinejad said at a news conference.

But the crackdown goes beyond the justice system. Books are more closely censored these days and newspaper editors are being told how to cover issues ranging from nuclear negotiations to local crime control.

“This is completely new and there hasn’t been such a thing before,” said Mashaallah Shamsolvaezin, head of Iran’s Association for Defense of Freedom of the Press.

The annual spring enforcement of Islamic dress codes in Tehran was stricter this year, spawning hundreds of arrests. Amnesty International says executions went from 94 in 2005 to 177 last year. Iran says none of the executions were political and many of those executed were drug traffickers caught in operations to halt opium and heroin smuggling from Afghanistan.

At least 33 women have been arrested in recent months at rallies seeking change on issues such as legalized polygamy, child custody and a marriage age of 13, said Nasrin Sotoudeh, a lawyer for some of the women. About a third received suspended prison terms of several years.

Even the smoking of water-pipes in teashops, a beloved tradition, has been banned, officially for health reasons.

Campus poetry nights have been canceled, along with commemorations of past student uprisings. Bus drivers and other workers have been fired and arrested for union organizing, and nearly 300 teachers were arrested after demanding higher pay.

“Unfortunately our authorities declare any gathering which is not according to their wishes as being illegal,” said Abdolfattah Soltani, a lawyer for bus workers and teachers.

An unknown number of cases remain designated as under investigation by the revolutionary court, keeping suspects unsure of their fate.

“The ones that we know are free,” he said. “It’s possible that others are being held in unofficial prisons.”

The Freedom Party’s public meetings have been banned for years. This year, supporters have been blocked from gathering even in a private house, Yazdi said.

American connections have come under particular scrutiny.

Haleh Esfandiari is one of four Iranian-Americans arrested while visiting Iran and charged with endangering national security. She directs the Middle East program at the Woodrow Wilson International Center for Scholars in Washington.

Parnaz Azima, a journalist who works for the U.S.-funded Radio Farda, is free on bail but she is barred from leaving the country.

Two men in custody are Kian Tajbakhsh, an urban planning consultant with George Soros’ Open Society Institute, and Ali Shakeri, a founding board member of the Center for Citizen Peacebuilding at the University of California, Irvine.

A judiciary spokesman said June 12 that a judge would complete his preliminary investigation of the four “within the next two or three days.”

On Friday, the spokesman, Alireza Jamshidi, said the investigation was still in its “final phases” and results would be announced in one or two weeks. The delay was not explained.

America has publicly allocated $66 million to promote change inside Iran, mostly through broadcasts of Persian-language news, entertainment and music from Washington and Los Angeles that Iranians can see using illegal satellite dishes.

Government supporters say Iran must protect itself from U.S.-sponsorship of civic activism that they say is aimed at overthrowing the government.

Even some government opponents understand Ahmadinejad’s fears. “I think that if America did not make announcements and provide financial support for regime change, then we would be more at ease,” said Yusuf Molaie, a university professor and lawyer for several Amir Kabir students.

But other opponents accuse the government of exploiting the U.S. threat to quash criticism of the flagging economy and Mr. Ahmadinejad’s failure to deliver on populist promises to share Iran’s oil wealth with ordinary people.

“He cannot fulfill those promises … therefore he is confronting those who make objections, like teachers, laborers and journalists,” said Ali Nikoo Nesbati, a spokesman for Strengthening Unity, a group that coordinates Iran’s reform-minded national university network of student Islamic Associations.

Mohammad Ali Sepanlou, a renowned poet and co-founder of Iran’s writers association, says more books are being censored and the rules are harsher.

He said publishers have always needed official approval to print and distribute books, but now they need fresh permission to reprint a book, and may have it censored if anyone complains about its content.

“With the exception of classic books and the books of those who are pro-government, almost every book is censored,” Sepanlou said. “Some lightly, some deeply.”

He estimated that 2,000 books now come out each year in Iran, a nation of some 70 million people, down from 4,000 five years ago.