Iran has blocked access to more than five million internet sites, whose content is mostly perceived as immoral and anti-social, a judiciary official was has said.
"The enemies seek to assault our religious identity by exploiting the internet," Abdolsamad Khoram Abadi, an adviser 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 targeted newspapers and other media, including websites and news agencies, of all political persuasions.