TEHRAN -- Iran has revealed the arrest of  26 men and women, accused of producing adult and child porn, both a severe violation of Islamic laws.

Conducted by the Islamic Revolutionary Guards in a marked change from their usual military activities, it's the biggest crackdown so far in Iran. A unit assigned to organized Internet crimes announced the shutdown of some 90 porn sites in late March and has been updating details with the inclusion of confessions from those arrested.

The BBC reports the suspects are charged with promoting orgies and incest, uploading sex clips of young girls and also making light of Shia Islamic beliefs such as the death of the grandson of the Prophet Muhammad.

Some were caught through e-mail investigations, while two men and one woman who used to live outside Iran were reportedly "tricked" into returning and then arrested, according to their friends.

Iranian officials claim the porn ring was "supported" by countries hosting the sites, including the U.S., Canada and Israel.

Porn site access is supposed to be blocked in Iran, but surfers there manage to get through; one of the sites showed 300,000, registered Iranian users, some video clips downloaded at least 6 million times.

"Over half of Internet users in Iran have admitted searching for porn and about one-third of them do it every day," Tehran sociologist Saeed Madani told the BBC.

Because young men and women are generally forbidden to socialize in public, Madani believes it's led to a greater demand for adult material, especially in the most urban areas of the country, where Web access has increased markedly.