Paris-based Reporters Without Borders said in statement Saturday that 28 journalists and bloggers are currently being held _ including two arrested last week: a blogger supporting women's rights and a reporter for a business daily.
The group said reporters have been repeatedly threatened, summoned by the intelligence services and given long prison sentences after questionable judicial proceedings.
Largely swept off the streets, the opposition relies on the Web and cell phone service to organize rallies and get its message out.
The call for Monday's demonstrations was put out on dozens of Web sites run by supporters of opposition leaders Mousavi and Mahdi Karroubi, who both ran against Ahmadinejad in the June 12 election. Most of those sites have been repeatedly blocked by the government, forcing activists to set up new ones.
Monday's demonstrations mark the anniversary of the 1953 killing of three students at an anti-U.S. protest during the rule of Shah Mohammad Reza Pahlavi, a close American ally.
Since the 1990s, that anniversary has served as an occasion for protests by those urging Iran's Islamic leadership to allow more social and political freedoms.
Signs have mounted in recent days of a potentially explosive confrontation, especially if the protesters take their demonstrations off campuses. Extra police and other security personnel were deployed around Tehran University Sunday, and the nation's police chief, Gen. Ismail Ahmadi Moghaddam, warned that security forces will crush any protests.
The joint forces also detained seven Taliban fighters during the operation over the past three days, he further said.
Meanwhile, Taliban purported spokesman Qari Yousuf Ahmadi in talks with media via from undisclosed location claimed that the outfit's fighters have blown up three tanks of foreign troops and killed over a dozen soldiers, a claim rejected by Ahmadi as groundless.
The operation, dubbed "Cobra's Anger", began Friday morning in Nawzad district with the involvement of some 1,000 U.S. Marines and 150 Afghan soldiers to disrupt Taliban supply routines and communication lines in the former Taliban stronghold.
The group said reporters have been repeatedly threatened, summoned by the intelligence services and given long prison sentences after questionable judicial proceedings.
Largely swept off the streets, the opposition relies on the Web and cell phone service to organize rallies and get its message out.
The call for Monday's demonstrations was put out on dozens of Web sites run by supporters of opposition leaders Mousavi and Mahdi Karroubi, who both ran against Ahmadinejad in the June 12 election. Most of those sites have been repeatedly blocked by the government, forcing activists to set up new ones.
Monday's demonstrations mark the anniversary of the 1953 killing of three students at an anti-U.S. protest during the rule of Shah Mohammad Reza Pahlavi, a close American ally.
Since the 1990s, that anniversary has served as an occasion for protests by those urging Iran's Islamic leadership to allow more social and political freedoms.
Signs have mounted in recent days of a potentially explosive confrontation, especially if the protesters take their demonstrations off campuses. Extra police and other security personnel were deployed around Tehran University Sunday, and the nation's police chief, Gen. Ismail Ahmadi Moghaddam, warned that security forces will crush any protests.
The joint forces also detained seven Taliban fighters during the operation over the past three days, he further said.
Meanwhile, Taliban purported spokesman Qari Yousuf Ahmadi in talks with media via from undisclosed location claimed that the outfit's fighters have blown up three tanks of foreign troops and killed over a dozen soldiers, a claim rejected by Ahmadi as groundless.
The operation, dubbed "Cobra's Anger", began Friday morning in Nawzad district with the involvement of some 1,000 U.S. Marines and 150 Afghan soldiers to disrupt Taliban supply routines and communication lines in the former Taliban stronghold.