Iran has acknowledged that satellite signals there are being jammed, but it remains unclear which government agency is responsible as officials continue to deny involvement, reports Radio Free Europe/Radio Liberty’s Persian Letters blog.

In an Aug. 21 interview, Reza Taghipour, Iran’s minister of communications and information technology, said his department was not involved in the jamming and in fact was “seriously” pursuing the case. But a day later, Hossein Ali Shahriari, head of the Iranian parliament’s health committee, said the communications ministry was “very well” aware of the source of the jamming but “doesn’t want to announce it.” The Iranian Communication Regulatory Authority also has denied knowing anything about the source of the jamming.

The Islamic republic has long used signal jamming to disrupt the free flow of information, routinely blocking the signals of international broadcasters to prevent critical media coverage from reaching Iranians.

Meanwhile, Tehran council member Massoumeh Ebtekar said recently that jamming is a health hazard for residents of his city. “What we know is that these signals have an impact on people’s health and the body’s cells,” he said. “As an immunologist and researcher, I’d say that these signals could be the source of many illnesses.”