"There are more than 3,000 Satan-worshipping cults in the world and about 50 of them have entered Iran," deputy police chief Hossein Zolfaghari was quoted as saying by Etemad newspaper.

He said about half of those groups were active and that about 200 books on the subject had been translated, printed and distributed.

Such groups commonly "deviate from conventional religions, make false promises, sexually exploit" and "are tasked with (promoting) Islamophobia," Zolfaghari said.

"Satan-worshippers wear broken-cross and skeleton necklaces and rings, drink alcohol and dance in their ceremonies. They believe they should defy religions, especially Islam, do as they want and drag the world into anarchy."

Zolfaghari said some of these groups sought to "attract young people by playing satanic music during (private) sports activities,"  had books in English and "gather in parks to talk about events across the country and Satan."

Iranian authorities sometimes link hard rock and heavy metal music and their icons with Satan worship.

Last year police arrested 230 people in a raid on a "Satan-worshipping" underground rock concert near Tehran amid a nationwide crackdown on attire and behaviour deemed contrary to Islamic law.

About two third of Iran's 70 million Shiite-majority population are under 30 years old.