Harare/Johannesburg  - Zimbabwe's presidential run-off election between President Robert Mugabe and opposition leader Morgan Tsvangirai will take place on June 27, Zimbabwe Electoral Commission head George Chiweshe told Deutsche Presse-Agentur dpa Friday.

The date was also contained in a government gazette that appeared Friday.

Mugabe, 84, leader since independence in 1980 and accused of gross human rights violations, and former national trade union leader Tsvangirai are due to square off again after neither achieved over 50 per cent of the vote needed for outright victory in March 29 elections.

Zimbabwe's laws call for a run-off within 21 days of the results being announced but ZEC on Wednesday extended the window for a second round to 90 days from the results on May 2.

After a five-week wait for the result, Tsvangirai was given 47.9 per cent of the ballot, to 43.2 per cent for Mugabe.

Human rights organisations, churches and diplomats report that ruling party militias are carrying out a nationwide campaign of vengeance attacks on supporters of Tsvangirai's Movement for Democratic Change to terrorise them into voting for Mugabe in the run-off.

The MDC has called the postponement of the election "illegitimate and unconstitutional." (dpa)