Iran's official news agency says the judiciary has set up a special prosecutor's office for offenses related to media and culture.
The move signaled new restrictions on journalists and artists, many of whom supported widespread protests against the re-election of President Mahmoud Ahmadinejad in 2009.
The news agency Irna reported Sunday that the new department will operate under Tehran's chief prosecutor and that a special court will also be established.
The 2009 protests erupted after Ahmadinejad was re-elected in a vote opposition members say was marred by massive fraud. Authorities prosecuted many journalists, bloggers and filmmakers on security charges related to the post-election turmoil.
An Iranian reformist website says the opposition is defying a government warning and calling on people to stage a rally in solidarity with Tunisian and Egyptian protesters.
Kaleme.com published a statement Sunday by a council of opposition groups inviting people to attend a peaceful rally on Monday.
The opposition statement also accused the government of double-standards, by voicing support for Egyptian and Tunisian protesters while refusing to issue permission for Iranian political activists to stage a peaceful demonstration.
Last week, authorities rejected the opposition's request to stage the14 February rally and warned of repercussions if it does.
Tehran's rulers crushed protests following the country's disputed 2009 presidential election. The opposition has not managed to stage protests in more than a year.
Western spies are seeking someone with impaired mental faculties to immolate himself and ignite an uprising in Iran as occurred in Arab nations, the head of the country's powerful militia said Sunday.
Commander Mohammad Reza Naghdi, who heads Iran's feared Basij militia made up of hundreds of thousands of volunteers, said Western intelligence agencies want to trigger events in Iran similar to those in Egypt and Tunisia.
"Western intelligence agencies are searching for a mentally challenged person who can set himself on fire in Tehran to trigger developments like those in Egypt and Tunisia," Naghdi was quoted as saying by Fars news agency. "They (the West) are very retarded and think by imitating such actions they can emerge victorious."
Naghdi's remarks come as Iran's opposition leaders seek to hold a rally on Monday in support of Arab uprisings but which regime backers believe is a ploy to stage fresh anti-government demonstrations.
The uprising in Tunisia which led to the fall of president Zine El Abidine Ben Ali was triggered by the self-immolation in December of a young student.
Copycat self-immolation bids ocurred in Egypt in the days leading up to January 25, when protesters first took to the streets of Cairo to demand the ouster of strongman Hosni Mubarak.
The 18-day popular uprising in Egypt ended on Friday when Mubarak handed power to the military after 30 years of unpopular autocratic rule.
Iran has supported uprisings in Arab nations but has refused permission to its own opposition leaders to stage a rally on Monday.
Iranian authorities crushed opposition rallies which erupted in Tehran soon after the re-election of President Mahmoud Ahmadinejad in 2009.
Dozens of people were killed, hundreds wounded and thousands arrested in a heavy handed crackdown by authorities and Basij militiamen on protesters who accused the authorities of rigging the elections which returned Ahmadinejad to power.