Egypt withdrawn the licence to broadcast of rolling news channel Al-Jazeera and shut down its Cairo bureau.
The state-run Middle East News Agency (MENA) reported that the order took effect from yesterday.
Transmission ended around an hour after that announcement and as troubles escalated the BBC World Service condemned "deliberate assaults" on its journalists.
An Al Jazeera spokesman said that the company would continue its strong coverage regardless.
"Al Jazeera sees this as an act designed to stifle and repress the freedom of reporting by the network and its journalists," the broadcaster said in a statement.
"In this time of deep turmoil and unrest in Egyptian society it is imperative that voices from all sides be heard; the closing of our bureau by the Egyptian government is aimed at censoring and silencing the voices of the Egyptian people."
The move to close Al Jazeera brought immediate condemnation from journalistic organisations across the globe, including from the Association for International Broadcasting, the Committee to Protect Journalists and Reporters Without Borders.
'By banning Al Jazeera, the government is trying to limit the circulation of TV footage of the six-day-old wave of protests,'Reporters Without Borders secretary-general Jean-FranÃ§ois Julliard said.
'Thus totally archaic decision is in completely contradiction with President Hosni Mubarak's promise of 'democratic' measures on 28 January.
'It is also the exact of opposite of the increase in freedom sought by the Egyptian population."
The move to block Al-Jazeera came as violent protests on the streets of Cairo against the 30 year reign of President Hosni Mubarak stretched into a seventh day.
Police were ordered back onto the streets as protesters called for a general strike as more demonstrators were killed.
The National Union of Journalists has joined with the International Federation of Journalists in calling for an end to attacks on journalists who have been detained and beaten during protests in Egypt.
According to the NUJ, at least ten Egyptian journalists were detained during a protest held outside the Egyptian Journalists Syndicate (EJS) office in Cairo and foreign reporters were arrested and beaten while covering the protests.
Guardian reporter Jack Schenker was beaten by police and arrested last week as he covered street riots.
The IFJ has since said that local and foreign journalists had been targeted by police and has listed numerous incidents of arrests and violence against journalists on its website.
In addtion, BBC World Service said Assad Sawey, its correspondent in Cairo, was deliberately assaulted by police while reporting protests last week.
Sawey was reporting on a police baton charge when he was surrounded by men who appeared to be plain clothes security men, the BBC said. Despite clearly identifying himself as a journalist for the BBC, he was repeatedly hit, including blows to the head. He also had his camera confiscated.
He was arrested before being released with no charge. Assad subsequently received medical attention for a wound he sustained to his head. He is continuing to report on the current situation in Cairo on behalf of the BBC.
Peter Horrocks, BBC Global News Director, said:
"The BBC condemns this assault on one of our correspondents by the authorities. We shall be forcefully protesting this brutal action directly to the Egyptian authorities.
"It is vital that all journalists, whether from the BBC or elsewhere, are allowed to do their job of bringing accurate, impartial eye witness reports to audiences around the world without fear."