Zimbabwe arrests US citizen over 'plot'

Zimbabwean police have charged an American citizen with plotting to overthrow a constitutionally elected government, her lawyer says.

Martha O'Donovan, who works for Magamba TV, which describes itself as Zimbabwe's leading producer of political satire, had earlier been charged over a tweet that appeared to insult President Robert Mugabe.

In a statement to police, O'Donovan denied the allegations against her as "baseless and malicious".

O'Donovan was picked up in a dawn raid on her Harare home, Zimbabwe Lawyers for Human Rights said in a statement on Friday.

Police raided her home with a search warrant requiring O'Donovan to give up her computers, mobile phones and other electronic devices.

Police accused the American of posting a message on Twitter last month that read, "We are being led by a selfish and sick man".

The police search warrant had shown that central to its investigation was a post on O'Donovan's Twitter feed referring to a "Goblin" whose wife and stepsons had imported a Rolls Royce, an apparent reference to 93-year-old Mugabe, though he was not named.