Police have arrested 120 people for attending a party in the forest in the northern province of Mazandaran, state media reported Sunday.
Iran considers any gathering of mixed sex as breaking the country’s segregation and morality rules.
“Members of this illegal tour... were arrested by the morality police and a lawsuit has been filed,” provincial judiciary chief Mohammad Sadegh Akbari said, quoted by state broadcaster IRIB.
Akbari said the “criminal acts” conducted in a forest near the city of Neka included “drinking alcohol, having illicit relationships, mixed-sex dancing and uncovering the hijab.”
Under its Islamic law since the 1979 revolution, Iranian women must wear a hijab that covers the head and neck while concealing the hair.
Many women have pushed the boundaries over the past two decades by allowing their veils to slide back and reveal more hair, especially in Tehran and other major cities.