Zimbabwean President Robert Mugabe. File photo: ANA

Johannesburg - Zimbabwe's Parliament has erupted in cheers as the speaker on Tuesday announced the resignation of President Robert Mugabe.

The speaker stopped impeachment proceedings to say they had received a letter from Mugabe with the resignation "with immediate effect."

It is an extraordinary end for the world's oldest head of state after 37 years in power.

Mugabe's resignation comes hours after parliament began an impeachment process against him on Tuesday that was set to bring his domination of a country he has ruled since independence nearly four decades ago to an ignominious end.

In the last week, Mugabe has clung on in the face of a collapse of his authority and a Monday deadline to quit.

Mugabe shocked many on Sunday when he was expected to resign, but instead gave what many considered a bizarre speech that focused on the country's unity while ignoring protests that had taken place the previous day.

The army seized power a week ago and there have been mass protests against him and calls to resign from many sides including on Tuesday from the ruling party's favourite to succeed him Emmerson Mnangagwa.

This is a developing story.

Associated Press