Three international broadcasters have strongly condemned Iran for its "deliberate electronic interference" in their broadcasts.
The BBC, Deutsche Welle and Voice of America said the jamming began on Thursday as Iran marked the 31st anniversary of the Islamic Revolution.
They said Iran was broadcasting freely around the world while denying its own people programmes coming from outside.
The BBC, Deutsche Welle and Voice of America said the Iranian authorities' jamming was affecting services on the Hotbird satellite, which covers audiences across Europe and the Middle East.
These include BBC Persian Television, the Voice of America Television Channel in Persian and Radio Farda; and Deutsche Welle's Television and Radio services. BBC World News - the English-language channel - was also jammed.
"We condemn any jamming of these channels. It contravenes international agreements and is interfering with the free and open flow of international transmissions that are protected by international treaties," the broadcasters said in a joint statement.
"The Iranian authorities are using the same satellite services to broadcast freely around the world including broadcasts in English and Arabic; at the same time they are denying their own people programmes coming from the same satellites from the rest of the world," they added. See also post below
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