Iranian authorities have announced a new crackdown on models who post images of themselves online without their hair covered.

State television reported Monday that officials particularly targeted the picture-sharing application Instagram as part of an operation it called Spider II.

It said authorities arrested eight people out of some 170 people identified as being involved in modeling on social networks including 58 models, 59 photographers and makeup artists.

Instagram, owned by Facebook, did not immediately respond to a request for comment.

In recent years, Iranian women in Tehran especially have increasingly worn the mandatory scarf loosely on their head, drawing the ire of conservatives in the Islamic Republic amid a larger struggle over the country's future.