Iranian authorities have detained several organizers of a gathering attended by thousands marking the birth of the pre-Islamic King Cyrus the Great, the founder of the Achaemenid Empire.
Iranian media quote Fars Province prosecutor Ali Salehi as saying the activists were detained because of "norm-breaking and anti-values" slogans that were chanted during an October 28 gathering in the province.
It wasn't clear how many people were detained.
Videos of the event posted on social media show dozens of Iranians admiring Cyrus as the founder of the First Persian Empire, with some criticizing the Islamic republic's role in Syria and others chanting slogans in favor of the Pahlavi dynasty that ruled Iran before the 1979 revolution.
In recent years in October, some Iranians have celebrated Cyrus the Great at his tomb in the town of Pasargad, some 800 kilometers south of Tehran.
Clerics who came to power after the 1979 revolution generally disapprove the celebration of pre-Islamic icons.
Senior cleric Ayatollah Nuri Hamedani criticized the October 29 gathering over the weekend, saying that the founder of the Islamic republic, Ayatollah Ruholllah Khomeini, had called those who celebrate Cyrus the Great "antirevolutionaries."