The growing movement has largely taken place in the shadow of a global diplomatic crisis. For months, as the world focuses its attention on Iran's nuclear intentions, Iranian feminists have been bravely fighting the country's entrenched patriarchy.

But even as the world has taken little notice of the activists, Iranian authorities have. Accusing the women of being a threat to national security and of using foreign funds to stir up dissent in Iran, Tehran, in recent months has been doing what it can to crush the home-grown feminist movement.

The most recent move in the ongoing crackdown was the arrest of prominent activist Zeinab Peyghambarzadeh earlier this month. The 21-year-old was arrested after she had gone to court to answer questions about her participation in a rally in March. The crackdown, however, has been gaining steam for months.

In recent months Peyghambarzadeh and her fellow activists have been organizing a series of demonstrations across the country to rally against patriarchal laws and structures in Iran, including polygamy, unfair inheritance laws, and a lack of custody rights in divorce settlements. They have likewise been going out to talk with Iranian women in the streets, universities, schools and factories. They have also been active on the Internet, setting up a number of Web sites dedicated to women's issues.

The most prominent supporter of the movement is Shirin Ebadi, the Nobel Peace Prize Laureate. According to Ebadi the popular support for the women's movement has unsettled the regime in Tehran. They see the feminists as calling into question the Iranian constitution, which is based on Shariah law and effectively treats women as second-class citizens.

"With a correct interpretation of Islam we can have equal rights for women," Ebadi said in a recent interview with Radio Free Europe, adding that women in Iran "haven't had the opportunity ... to demonstrate their capabilities." In an earlier interview with SPIEGEL ONLINE, Ebadi said that "harassment is a fact of life for someone pursuing human rights in Iran."

On March 4, over 30 women, including Peyghambarzadeh, were arrested after they attended a protest rally in support of a number of arrested activists. Police loaded the 31 women into a bus and drove them to Tehran's Evin prison where they were blindfolded, forced to wear chadors and interrogated, before being released over the following weeks.

According to Reporters without Borders, four other women's rights activists were given prison sentences in March for using the Internet to demand better conditions for women in the country. The "cyber-feminists" had been trying to collect a million signatures to call for a change to discriminatory laws. The women were found guilty of "violating national security," and given sentences ranging from six months to a year.

"Despite the constant harassment of its members, the Iranian feminist movement is growing and is alarming the government," Reporters without Borders said in a statement. "The Internet is now a battle-ground between these women, who are just demanding the same rights as men, and a regime that remains as rigid as ever."

The series of arrests are an indication that the small progress that had been made under the former reformist president Mohammad Khatami is now being rolled back by his successor, the hard-liner Mahmoud Ahmadinejad, since he was elected in 2005.

The Iranian police are also ramping up their inspections of women to ensure they are adhering to the Islamic dress code. The annual spring offensive to make sure women are covering up enough has been particularly strict this year. And the government in Tehran is now drafting a law to limit female students to half the places in college, instead of the 65 percent they currently occupy.