Al-Jazeera has been criticised by many Arab governments for its coverage of the anti-regime uprisings Iran is jamming broadcasts by Qatar-based news channel Al Jazeera, according to a document from satellite operator Arabsat obtained by Reuters on Tuesday, with the broadcaster saying it believed it was because of its coverage of Syria.
Interference is coming from two locations in Iran, one west of Tehran and the other near the northwestern city of Maraghen, the document showed.
"We believe that this is happening because of our coverage of Syria," a senior official at Al Jazeera told Reuters, declining to be identified.
The official said they believed other channels in the region had also been jammed.
Neither Arabsat nor Iranian officials were immediately available for comment.
Iran's regional ally Syria has mostly barred foreign media from the country and has criticised Al Jazeera's coverage of the upheaval there.
On Saturday Al Jazeera announced a new frequency for Arabsat viewers due to "continued interference".
"Over the past few months, Al Jazeera has faced sustained interference to our satellite transmissions," the channel said in a statement.
Al Jazeera, owned by the Qatari government, aired round-the-clock coverage of uprisings that brought down veteran rulers in Tunisia, Egypt and Libya last year.
It frequently has had difficulties with Western and Arab governments in a region where governments have traditionally kept tight control over state media.
Syrian President Bashar al-Assad vowed on Tuesday to strike "terrorists" with an iron fist and derided the Arab League for its attempts to halt violence in the 10-month-old revolt against his rule in a speech at Damascus University.
Syria, Assad complained, was the target of a relentless foreign media campaign. Blaming unrest on "outside planning", he said: "The outside now regrettably includes Arabs."