Iranian police briefly detained two European diplomats at a mixed-gender party, which are illegal under Iranian law, the semi-official Tasnim news agency said Saturday.
A British and a Dutch diplomat were released in the early hours of Friday morning after being identified as foreign government workers.
The report said the party in the capital, Tehran, was attended by several men and women, but did not elaborate or specify if alcohol was present.
In Iran, it is illegal to drink alcohol or hold mixed gatherings of men and women who are not related.
Last week, the Telegraph reported that Iran’s hardline judiciary was cracking down on what the regime considers to be religious and moral crimes committed in public spaces.
Iranians were warned by authorities they would face criminal prosecution for violating the Muslim holiday of Ramadan by eating during fast hours, listening to music or flouting the strict gender-based modesty rules in public spaces, according to the report.
The Telegraph linked the draconian crackdown to the regime’s fears of public criticism and protests amid growing economic and diplomatic uncertainty as tensions with the US have risen in recent months.