Voice of America, the BBC and Deutsche Welle have condemned Iranian authorities for what they say is the illegal jamming of their broadcasts to Iran.
The international broadcasters released a joint statement Friday accusing Iran of jamming their shared satellite. They said the move violates international agreements and called on satellite operators to pressure Iran to stop.
The U.S. State Department said Iranian attempts to block nearly all media coverage of Thursday's anti-government protests in Tehran show the government there "fears its own people."
Iran also reportedly shut down phone and Internet services.
Iranian authorities have accused international media of helping stir the unrest following last year's disputed presidential election. Massive protests erupted after the June election, which returned President Mahmoud Ahmadinejad to power.
Thursday's protests coincided with rallies marking the 31st anniversary of the founding of the Islamic Republic.
Opposition activists say Iranian security forces cracked down on protesters with tear gas, batons and arrests. Opposition Web sites say security officials attacked leading reformist politicians Mehdi Karroubi and former President Mohammad Khatami, as well as the wife of main opposition leader Mir Hossein Mousavi.
The reports could not be independently verified because of Iran's ban on foreign press coverage.
Some information for this report was provided by AP, AFP and Reuters.