The Zimbabwean parliament has started impeachment proceedings against President Robert Mugabe.

Mr Mugabe, who has been in power since independence in 1980, is accused of allowing his wife to "usurp constitutional power" by trying to position her as his successor.

The motion to remove him is supported by Mr Mugabe's own Zanu-PF party.

Mr Mugabe has refused to resign despite last week's military takeover, and days of protests against his rule.

The motion for impeachment was moved and seconded at parliament but lawmakers have adjourned to a hotel conference centre to debate it in a joint session.

Parliament speaker Jacob Mubenda said the motion was "unprecedented in the history of post-independence Zimbabwe".

There have been rallies and prayer meetings outside the parliament building in support of the move to impeach Mr Mugabe, who is 93.