The leader of the unregistered Democratic Party of Iran, Abbas Khorsandi, is among the latest targets of the Iranian security services. Khorsandi was sentenced last week to eight years in prison after being found guilty of threatening Iranian state security by setting up "an illegal political group."
A 50-year-old economics professor in the northern town of Firuzkuh, Khorsandi was arrested about seven months ago and has spent more than two months in solitary confinement in Tehran's notorious Evin prison.
Khorsandi's wife, Forozandeh Seylespur, tells RFE/RL that her husband has become a prisoner of conscience because of his stated opposition to the Iranian government.
"He got this sentence only for holding opposing views," Seylespour says. "He hasn't done anything to justify getting such a sentence. He was only involved in writing. He has acted -- in a totally peaceful manner -- as a writer and human rights activist. He has voiced his views only through the pen and in speeches."
The news of Khorsandi's lengthy prison sentence followed reports about the arrest of another peaceful campaigner, Khadija Moghaddam.
The women's rights activist and member of the One Million Signatures Campaign was arrested by security officers, who Moghaddam said "forcibly entered her home" and treated her in a "despicable manner."
Moghaddam has reportedly been charged with spreading propaganda against the state, disrupting public opinion, and acting against national security.
The court has set a bail of some $110,000 for her release.
The One Million Signatures Campaign was launched in 2006 as a nonpolitical movement that calls on parliament to change what it calls "discriminatory laws in Iran," including laws on inheritance, divorce, and child custody, which the campaign says treat women unfairly.
In an interview with RFE/RL earlier this year, Moghaddam said it is time to abolish such laws, which were set up many centuries ago.
"What I say now is the opinion of all Iranian women," Moghaddam said. "We live in a century when women take an active part in political, economic, social, and cultural affairs alongside men. We work, we study, and we should not be considered as half of a man. Sixty-four percent of [Iranian] university students are women. They cannot accept a 1,400-year-old rule that considers a woman as half of a man."
Some 600 Iranian activists have signed an open letter condemning Moghaddam's arrest and calling for her release. "Moghaddam has been active for years in creating jobs for women and forming women's cooperatives," the letter says. "Who would believe that she has harmed national security or caused public offense?"
Rights activists say that the arrests of peaceful campaigners, independent journalists, and anyone who is critical of the government have become routine under President Mahmud Ahmadinejad's government. International organizations including Amnesty International and Reporters Without Borders (RSF) have harshly criticized Tehran for cracking down on all voices of dissent in the country.
RSF has called Iran "the biggest prison in the Middle East" for journalists and authors whose views differ from the government's. According to the media rights group, dozens of Iranian journalists and rights campaigners have been imprisoned and accused of undermining national security for "simply being outspoken."
On April 5, 30-year-old Elham Yaqubi was arrested and accused of threatening national security for taking part in a peaceful demonstration.
On the same day, Parvin Ardalan, an award-winning rights activist, was charged with spreading propaganda against the state, a month after she was banned from traveling to Sweden to collect her Olof Palme Award.
Ardalan has been summoned to court at least three times this year. She received a summons two days after the Olof Palme Foundation announced that she had won the prestigious award for human rights activists.