"The enemies seek to assault our religious identity by exploiting the Internet," Abdolsamad Khoram Abadi, an advisor to Iran's prosecutor general, was quoted by Kargozaran newspaper as saying.
The Internet "inflicts social, political, economic and moral damage, which is worrying," he said, adding that "social vice caused by the Internet is more than that by the satellite network," Mehr news agency reported.
With about 21 million users, the Internet is widely popular in Iran, which information ministry officials say ranks among the top 20 user countries.
In recent years, Internet service providers have been told to block access to political, human rights and women's sites and weblogs expressing dissent or deemed to be pornographic and anti-Islamic.
The ban has also targeted such popular social networking sites as Facebook and YouTube, as well as news sites.
Iran's reformist press was hit by a massive crackdown in 2000, and many journalists turned to blogging after their publications were shut down.
The closures have continued under President Mahmoud Ahmadinejad, elected in 2005, and have targeted newspapers and other media, including web sites and news agencies, of all political persuasions.
Conservatives have also warned against "cyber imperialism" targeting developing countries.
In its latest edition, Sobh-e Sadegh, the publication of Iran's Revolutionary Guards, said, "The Internet, satellite (channels) and text messages played an important role in colour revolutions in Serbia, Ukraine and Georgia."
The weekly said Internet search engines Yahoo and Google, BBC and CNN televisions and even international news agencies including "Reuters, Associated Press, UPI, AFP and DPA" operated as "tools of diplomacy conducted through media."
The magazine accused the European Union of seeking to "develop anti-Iranian cyber space" by supporting dissident bloggers.
Despite a strict ban on satellite television, dishes dot many Iranian rooftops and people have access to dozens of Persian-language channels, including the Voice of America, broadcasting a daily dose of politics and entertainment.
Islamic republic officials have been concerned about BBC Persian-language television which is yet to be launched and warned against interviewing or cooperating with such media.
The head of Iran's state-run television recently said that 30 percent of Iranians watch satellite channels, but observers say the figures are likely to be higher.
