Iranian judicial authorities in Sirjan have announced the arrest of four individuals charged with “propaganda activities against the regime and insulting officials in the Facebook cyber space.”

ISNA reports that Sirjan Prosecutor Mehdi Bakhshi announced that “propaganda activities against the regime and insulting officials” as well as “posting pictures that do not observe hijab (Islamic attire)” will be subject to prosecution.

Facebook is one of the many sites that authorities block in Iran. While the Islamic Republic has announced its opposition to the site, some government supporters have been praised for propagating state views on the site.

Iran’s Supreme Leader Ayatollah Khamenei has said that posting on Facebook is acceptable so long as it does not “promote corruption, the publication of falsehoods, or strengthen enemies of Islam and Muslims.”

In addition to the arrest of four individuals linked to Facebook, the Sirjan Prosecutor announced that there have been previous arrests on similar charges, and he warned the public that they should refrain from questionable activities on the web or “face heavy sentences.”