The BBC has apologised for a second fake news story in a week, after saying a major incident had occurred during a live TV show from Buckingham Palace.
Huw Edwards is the face of the nightly 10 O'Clock News on BBC One
Newsreader Huw Edwards opened the Party at the Palace broadcast - watched by seven million - with a newsflash.
It announced the pretend loss of the Queen's handbag as part of the show, but 78 people complained.
Last week police criticised a hoax report on BBC Radio 2 which said Soham killer Ian Huntley had died.
It was broadcast as part of a discussion on Jeremy Vine's lunchtime show about the consequences of a UK run by tabloid news editors.
On Sunday, Edwards informed television viewers of a major incident at the palace before crossing to colleague Sophie Raworth.
Many of the complaints described the report as being "in poor taste", while one viewer said: "It was the most foolish gag I have ever heard."
However, it became clear it was not a real bulletin when she started to interview comedian Ronnie Corbett - dressed as pantomime character Buttons - about the handbag.
Another told the BBC: "We had a daughter caught up in the London bombings and a granddaughter at the palace, and I was terrified when I saw this."
"It was so realistic," said a third complaint, "I thought there had been another terror attack."
The BBC's head of television news, Peter Horrocks, wrote in The Editors blog that it had been assumed that people would realise the report was part of "the fun and fantasy" of the party.
However in retrospect, he said he could "see the combination of Jonathan Ross's hurriedly broken off introduction, then the newsroom with Huw's sombre expression could have led some to have concern."
The party was one of several events marking the Queen's birthday
Mr Horrocks continued: "All I can do is apologise for anyone who was momentarily misled."
A BBC spokeswoman described the report as being "an integral part of the night's entertainment" and insisted the appearance of Ronnie Corbett as Buttons would have "quickly made it clear that this was not a real newscast".
She said the BBC was "sorry that some people did not appreciate the joke".