Johannesburg, Harare - Zimbabwe's President Robert Mugabe has dismissed opposition claims of violence ahead of next week's presidential run-off election, saying the claims were aimed at tainting the vote, state media as reported.

The Herald newspaper quoted the 84-year-old Mugabe speaking at a rally in the country's second city Bulawayo on Friday as saying: "They have been saying their supporters are being beaten up by our soldiers. They say this so that they can later say the elections were not free and fair, which is a damn lie!"

Mugabe's utterances come amid claims by the opposition Movement for Democratic Change (MDC) that the Zanu-PF militia and army have killed about 70 of its supporters and displacing more than 30,000 people.

Morgan Tsvangirai, the MDC leader, has been detained by police five times while campaigning while a number of MDC leaders are either on the run or in jail. The party's secretary-general Tendai Biti faces capital punishment after being charged Thursday with treason along with other three charges. Biti in jail for more two weeks now was ordered to remain there until at least July 7.

Meanwhile, late Friday Zimbabwe's police chief Augustine Chihuri said the police would employ "all necessary force" to quell violence. Chihuri said the MDC was the "main culprit" behind political violence in the country.

Tsvangirai beat Mugabe in the March election but failed to acquire an absolute majority.

Mugabe - presiding over a collapsing economy - suffered his first defeat since Zimbabwe's independence in 1980. He has vowed that he will go to war if the opposition wins the Friday run-off. (dpa)