BBC radio and TV news programmes have been badly affected by a 24-hour walkout by journalists in a row over compulsory job losses.
The flagship Radio 4 Today programme was replaced with pre-recorded features, while national and regional TV news bulletins were hit.
The National Union of Journalists (NUJ) said the walkout was being strongly supported by its members, who mounted picket lines outside BBC offices and studios across the country. The BBC said it was "disappointed" with the industrial action but insisted it has to make "significant" savings.
Foreign correspondents and news readers who are NUJ members joined the stoppage, which led to a number of national radio news bulletins being cancelled, including Today, the World At One and the World Tonight. The corporation said there would be a 30-minute bulletin on BBC1 at lunchtime, but no regional news at 1.30pm.
Michelle Stanistreet, NUJ general secretary, 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."
She added: "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."
The NUJ said its members 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.
A BBC spokesman said: "We understand how frustrating and difficult situations involving redundancies can be, but it is disappointing the NUJ have chosen to take this action. We are working hard to ensure that we succeed in getting staff redeployed wherever we can and will continue to work with the unions to ensure that their members receive the right redeployment support."
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.
A BBC spokesman added: "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."