The Chinese authorities have forbidden radio and television presenters from speaking in regional accents.

Under a new law that came into effect on Monday, presenters or actors in television programmes must speak in standard Mandarin.

If they fail to do so or use incorrect grammar, they could be sent for retraining.

Correspondents say it is unclear how strictly the law will be enforced.

They say the new regulations could target broadcasters speaking Mandarin with Taiwanese or Hong Kong accents, which are becoming increasingly popular with young people.

Beijing has long tried to promote standard Mandarin across China, where hundreds of dialects are spoken. The new regulations do not apply to programmes in regional dialects.

From the newsroom of the BBC World Service