Tehran - Iran has decided to block more websites and crack down on internet bloggers, Tehran prosecutor Saeid Mortazavi said Wednesday.

"We will harshly confront those who run anti-religious, immoral and decadent sites," Mortazavi told Fars news agency without further clarifying.

He said computer experts and two officials from the prosecutor's office have formed a team to identify and block those websites.

The prosecutor especially referred to sexual websites "which have caused concern among Iranian families."

Local internet providers in Iran have also been ordered to filter political Farsi-language sites, especially by local bloggers critical of the Islamic system.

Sexual sites are totally taboo in Iran and even ordinary information sites on books or films are sometimes blocked if their titles contain terms such as sex or even kiss.

Besides the "immoral sites," numerous other sites are blocked by Iranian authorities, including popular ones such as You Tube, Facebook and Orkut, as well Farsi-language news sites of VOA and BBC.

The number of internet users, especially among the youth, has dramatically increased and reportedly reached more than 20 million.

Most users have also found ways to evade the state censors and get access to all sites via proxy tunnels.

Social networking sites such as Facebook and Orkut are very popular among young people, as they can date there without being bothered and or arrested by local vice enforcement.

Besides internet use, many Iranians also follow Western television programmes via satellite dishes. Although legally forbidden, the government has effectively given up the fight against the satellite dishes after its efforts in recent years turned out to be futile. (dpa)