Iran has shut down three daily newspapers critical of Mahmoud Ahmadinejad, the president, according to reports by state-run news agencies, Al Jazeera reported.
While no reason was given, the newspapers had been considered sympathetic towards those protesting over Ahmadinejad's disputed re-election in June.
The papers closed on Tuesday were Tahlil Rooz (Day's Analysis) in the southern city of Shiraz, and two of the most influential reformist newspapers Farhang Ashdi (Culture of Reconciliation) and Arman (Ideals) published in the capital, Tehran.
Some reports suggest the reason for the closure was a law which bans papers from receiving funds from abroad.
The government's closure of media outlets has become common in the past decade, during which time more than 100 independent and liberal newspapers and magazines have been banned.
A number of media outlets have been closed since Ahmadinejad's rise to power in 2005.
Several journalists have been detained on allegations of incitement as part of a media crackdown following the unrest that followed this year's elections.