Iranian police have arrested more than 260 people, including three European citizens, on suspicion of spreading satanism, the state-run IRNA news agency reported Friday.

The report said the suspects were arrested on Thursday night in Shahryar County, west of the capital of Tehran, for “spreading the culture of satanism and nudity.”

It was not clear how such a large number of arrests were made in one night — if the suspects were in one location, at some gathering or party, or not.

Gatherings where unrelated men and women are seen together are illegal in Iran and considered a sin under Islamic law.

IRNA's report said those arrested included 146 men, 115 women, and three European citizens, without mentioning their nationalities. IRNA said the suspects were caught in an “undesirable and obscene situation” with satanic symbols on their clothes and bodies.

Such symbols are common in some piercings, earrings or tattoos, but they are prohibited in Iran. The report said drugs and alcohol were confiscated from the suspects.

Iranian authorities occasionally arrest people taking part in mixed-gender parties and for drinking alcohol. Drinking alcohol is also illegal and Muslim men and women who are not related cannot mingle or dance together in public.