State television in Ivory Coast has been taken off air in areas outside of the main city of Abidjan.
Radio Television Ivorienne (RTI) is only terrestrial broadcaster in the country and a key source of news.
The BBC's John James in Abidjan says it has been one of the key elements keeping President Laurent Gbagbo in power since disputed polls in November.
Earlier, the region's central bank gave control of Ivory Coast's accounts to his challenger Alassane Ouattara.
Meanwhile, West African heads of state are meeting to urge President Laurent Gbagbo to step aside.
The UN and other international bodies have recognised Mr Ouattara of the 28 November poll, which was meant to unite the country after a civil war in 2002 split the world's largest cocoa producer in two.
The country's electoral commission ruled that Mr Ouattara had won, but the Constitutional Council said Mr Gbagbo had been elected, citing vote-rigging in some northern areas.
Our correspondent says RTI is still available in Abidjan but the satellite signal to relay stations has been cut.
It is not clear who turned off the feed or how the feed was switched off.
Since election day, RTI's coverage has been dominated by pro-Gbagbo supporters justifying the Constitutional Council's decision and condemning the United Nations for trying to provoke a "genocide" in Ivory Coast by backing the victory of Mr Ouattara, our reporter says.
Mr Ouattara's supporters tried to take control of the television station a week ago and install their own director-general, but the march ended in bloodshed with at least 20 deaths.
Access to the international media has been severely curtailed since the election results were announced, with most French news stations cut.
The 15-nation the Economic Community of West African States (Ecowas) has suspended Ivory Coast and heads of state are meeting in the Nigerian capita, Abuja to consider other measure.
The Ecowas chairman, Nigerian President Goodluck Jonathan has already written personally to Mr Gbagbo to ask him to step down, and offered him refuge.
No power sharing
There have been suggestions that member nations send in troops to strengthen the presence of the UN peacekeeping force, which has about 10,000 troops on the ground.
Ecowas sent peacekeeping forces to Liberia and Sierra Leone during their civil wars in the 1990s.
Mr Gbagbo has demanded that UN and French troops leave the country. A close ally even warned that they could be treated as rebels if they did not obey the instruction.
A power-sharing government has been ruled out.
"Something like a unity government or the sort of thing we have in Kenya and Zimbabwe are not on the table," Nigeria's Foreign Minister Odein Ajumogobia told AFP news agency. "We are resolute that Gbagbo has to step down."
On Thursday, the UN Human Rights Council expressed deep concern about the unrest, and unanimously adopted a resolution condemning the "atrocities".
A senior UN official said 173 people had died since the dispute began and its investigators had also found evidence of extrajudicial executions, more than 90 cases of torture and 500 arrests, as well as abductions, kidnappings, acts of sexual violence, and destruction of property.