Iranian authorities have blocked three websites: Tabnak, Baztab Emrooz and Iranian History.

Tabnak and Baztab Emrooz are two news sites, and Iranian History, as its name indicates, covered historical subjects.

The 12-member committee that determines which sites are unacceptable to the authorities has given no reason for its move against the three sites.

This comes shortly after the arrest of a least 12 journalists on Saturday and Sunday. The judiciary has not announced any charges against these journalists; however, the Mehr News Agency has reported that “the reason for the arrest of these individuals is linked to the cooperation that some of them gave to anti-Revolutionary, Persian-language media.”

Iranian journalists have been a consistent target of persecution by the authorities in recent years, especially after the elections protests of 2009.