"Cutting (their own) skin and sucking up the blood was among the indecent behavior of the group," Mehr News Agency quoted Colonel Abbas Hamedi of Iran's Revolutionary Guards in the city of Shiraz as saying.
He said a Guards intelligence unit launched an investigation into the all-male group about one year ago, leading to their arrest Sunday evening.
"The group's aim was to promote irreligious behavior," Hamedi, adding they had posted footage of their parties on the Internet.
The Islamic Republic, which bans alcohol and narcotics, last year said it would launch a crackdown on "indecent Western-inspired movements" such as rappers and satanists.
That move signaled a widening of a clampdown on "immoral" conduct launched in 2007 against women flouting rules dictating that they cover their heads and disguise the shape of their bodies in public, in line with Iran's Islamic system.
The crackdown against what clerics see as corrupt Western influence coincided with rising pressure on Iran by the West over its nuclear program. The United States and its allies say Iran wants to build an atomic bomb, which Tehran denies.
(Reporting by Hossein Jaseb and Hashem Kalantari; writing by Fredrik Dahl; editing by Mark Trevelyan)
