The authorities in Azerbaijan have shut down the country's biggest independent broadcaster, ANS.
They said ANS's licence was not renewed because it had violated the broadcasting law and disregarded official warnings and fines.
ANS head Vahid Mustafayev said he had not received any advance notification of the closure.
Critics of the Azeri government say the move is part of a wider campaign against freedom of speech.
The representative of the Organisation for Security and Co-operation in Europe (OSCE) in Baku, Maurizio Pavesi, said he was deeply concerned about the closure of a broadcaster widely considered to be the most objective in the country.
Broadcasting ended when police surrounded the ANS building in the capital and officials switched off its transmitters.
The independent television station's last transmission was a black and white message saying broadcasts had been suspended.
It now plans to appeal against the move.
Coincidentally, ANS says its radio channel was taken off the air during a report about an Azeri newspaper editor who had been taken to hospital after a hunger strike.
He had been protesting about the threat and closure of the offices of Azerbaijan's leading opposition newspaper, Azadlig.
Campaigners for media freedom have accused the Azeri government of curbing free speech in recent months by arresting journalists, launching punitive libel suits and trying to silence independent voices such as ANS, the BBC's Matthew Collin reports from the Caucasus.
President Ilham Aliyev has denied there is a problem with freedom of speech in Azerbaijan and the Azeri authorities say they are simply enforcing the law.
ANS has also been at the centre of a dispute over the rebroadcasting of news programmes from foreign media companies.
It was rebroadcasting radio news from the BBC's Azeri-language service and television material from the US channel Voice of America, our correspondent says.
The authorities say all rebroadcasts of foreign material must stop at the end of the year - a move which has raised more concerns about freedom of speech in Azerbaijan, Matthew Collin adds.