BBC strikes have disrupted news programmes, with viewers and listeners tuning in to find changed formats, or something completely different.

BBC1's Breakfast was off air, Today on Radio 4 ran a documentary and the regular 5 Live Breakfast hosts were replaced, owing to a 24-hour strike by journalists over compulsory redundancies.

BBC1's Breakfast was off air, replaced by a BBC News channel simulcast, while the regular 5 Live Breakfast hosts, Nicky Campbell and Rachel Burden, were replaced by Ian Payne and Julia Bradbury.

Listeners to Today were treated to a repeated documentary about the Russian revolution in the run up to 7am.

The BBC's flagship radio news programme ran as normal from 7am with regular presenters Sarah Montague and Justin Webb.

As part of the strikes, picket lines were mounted from midnight on Thursday outside BBC buildings across the country.

The National Union of Journalists predicted a "solid response" to the walkout and similarly, the BBC admitted it expected widespread disruption to services. The BBC said it was disappointed by the industrial action and apologised to viewers and listeners.

Negotiations with the NUJ over compulsory redundancies at BBC World Service and BBC Monitoring continued until the eve of the strike, but no agreement was reached.

The NUJ general secretary, Michelle Stanistreet, accused the BBC of "provoking" a strike over a handful of job losses, but the corporation said there were 100 posts for which compulsory redundancy was "regrettably unavoidable".

Stanistreet said the union offered a number of solutions to the dispute, adding that an offer from the conciliation service Acas for peace talks had not been taken up by BBC management.

"There are so many people who want to leave the BBC that this could be resolved through negotiations. The NUJ has a longstanding policy of no compulsory redundancies, and it is clear that our members at the BBC are fully prepared to stand up for their colleagues under threat," she said.

"Jobs are being saved and created at management level, but journalists are losing theirs. It is hard to avoid the conclusion that BBC management wants thousands of its journalists to go on strike rather than settle the dispute."

A BBC spokesman said: "We are disappointed that the NUJ is intending to strike and apologise to our audience for any disruption to services this may cause.

"We have had to reduce the number of posts in World Service and BBC Monitoring by 387, following significant cuts to the central government grants that support these services. In a significant majority of cases we have been able to reach this through voluntary redundancy orredeployment.

"However, there are in excess of 100 BBC posts for which compulsory redundancy is regrettably unavoidable, and this is our focus, regardless of whether staff are members of unions."

BBC staff are expected to strike again for 24 hours on July 29.