A strike by BBC journalists disrupted radio and TV news programmes today, with the threat of further action unless a row over jobs is resolved.
Flagship Radio 4 programmes including Today, The World At One, PM and The World Tonight were replaced with pre-recorded features, while national and regional TV news bulletins were also hit.
The National Union of Journalists said the walkout was strongly supported by its members, who mounted picket lines outside BBC offices and studios across the UK.
The BBC said it was "disappointed" with the industrial action, adding that it would not alter the fact that it has to make "significant" savings.
Foreign correspondents and news readers who are NUJ members joined the stoppage, which the union said was better supported than the last BBC strike in 2011.
The NUJ said it had not ruled out further industrial action, but was calling for more talks over compulsory redundancies and a moratorium on job cuts until new director general Tony Hall takes over in April.
Journalists across the BBC - in Scotland, in BBC South, the Asian Network, Newsbeat, Five Live, the World Service and English Regions - were at risk of compulsory redundancy, said the NUJ.
General secretary Michelle Stanistreet led journalists out of the BBC's new central London studios at midnight at the start of the walkout, and later joined a picket line.
She said: "NUJ members across the BBC are taking action to defend jobs and quality journalism at the corporation.
"They are angry and frustrated at the poor decisions being taken at the top of the BBC - decisions that are leading to journalists being forced out of their jobs and quality journalism and programming compromised.
"Instead of making sure that the redeployment process works properly in all areas of the BBC, managers are prepared to waste public money on needless redundancies and sacrifice the livelihoods of experienced and talented journalists, at the same time as advertising other jobs externally.
"It's particularly disappointing that the BBC has failed to engage meaningfully in attempts to resolve this dispute - an abdication of responsibility for a public service broadcaster."
A BBC spokesman said: "We are disappointed that the NUJ has gone ahead with today's strike and apologise to our audience for the disruption to services.
"Unfortunately industrial action does not alter the fact that the BBC has significant savings targets and as a consequence may have to make a number of compulsory redundancies.
"We have made considerable progress in reducing the need for compulsory redundancies through volunteers, redeployment and cancelling vacant positions and we will continue with these efforts."
The BBC, which is cutting around 2,000 jobs under its so-called delivering quality first programme, said 554 employees had left as a result of voluntary redundancy, 186 had been redeployed, and there have been 153 compulsory redundancies.