TEHRAN, Iran (AP) — Iranians sending images to a U.S.-based activist over an anti-headscarf campaign could face up to 10 years in prison.

The activist, Masih Alinejad, founded the "White Wednesdays" campaign in Iran to encourage women to post photographs of themselves without headscarves online as a way of opposing the compulsory hijab.

The semi-official Fars news agency on Monday quoted the head of the Tehran Revolutionary Court, Mousa Ghazanfarabadi, as saying that "those who film themselves or others while removing the hijab and send photos to this woman ... will be sentenced to between one and 10 years in prison."

The Islamic headscarf is mandatory in public for all women in Iran. Those who violate the rule are usually sentenced to two months in prison or less, and fined around $25.