(CNN) -- Iran on Sunday released on bail four journalists and a retired professor whom it had held for two months, the semiofficial Iran Labour News Agency reported.
The five prisoners had been held since they were arrested during a December 27 protest, according to ILNA.
The journalists are Abdolreza Tajik, Mashallah Shamsolvaezin, Behrang Tonkaboni and Mohammad Javad Mozafar, who is also a prisoners' rights activist, ILNA said. The news agency reported that the retired professor is Mohammad Sadeq Rabani.
Separately, ILNA reported that Tehran prosecutor Abbas Jafari Doulatabadi said Sunday that "detainees of recent unrest will be released due to the upcoming Iranian new year," which falls on March 21.
At the same time, ILNA quoted Doulatabadi as saying that those arrested on the Muslim holy day of Ashura, when the five prisoners freed on bail Sunday were rounded up, could face stiff penalties later. "The judiciary will imply more strict policies, and those who were arrested on Ashura Day will be confronted heavily by the judiciary," he said.
Mozafar and Tajik were released on $100,000 bail, according to Parleman News, the Web site of the minority reformists of the parliament. It did not mention the bail amount for the other two journalists. CNN was not immediately able to independently verify the bail amount.
The protests around Ashura were Iran's deadliest clashes since protests broke out last summer after incumbent President Mahmoud Ahmadinejad claimed more than 62 percent of the vote in national elections.
At least seven people were killed and hundreds were arrested on Ashura, witnesses said. The Iranian government has denied that its security forces killed anyone, blaming reformists for the violence.
Doulatabadi, the Tehran prosecutor, said Sunday that the judiciary and police forces will be on high alert near the Iranian new year. The judiciary and police will "confront those who disturb the norms of society with high explosives," he said.
The five prisoners were released Sunday from Tehran's Evin prison. ILNA did not release the professional affiliations of the journalists, but they were listed on opposition Web sites.
According to some main opposition Web sites, Tajik is an editor for Farheekhtegan, a weekly magazine, and a freelance journalist.
Shamsolvaezin has edited many of post-revolutionary Iran's first independent newspapers, including Kayhan, Jame'eh, Neshat and Asr-e Azadegan, according to opposition sites. Many of those have been closed down.
Tonkaboni is the editor of the magazine Farhang va Ahang, or Culture and Music, according to opposition sites.
Javad Mozafar is publishing director of Kavir, a publishing house, and vice president of the Committee for the Defense of Prisoners' Rights, according to opposition sites.
Sadegh Rabbani is a retired science professor at the University of Tehran, according to opposition sites.