With less than two weeks to go before an election run-off for the highest office in the land, Zimbabwe's President Robert Mugabe on Saturday ruled out a change of power in his lifetime.

Mugabe dismissed the opposition Movement for Democratic Change (MDC) party, saying: "These pathetic puppets taking over this country? Let's see. That is not going to happen."

"We are are prepared to fight for it (Zimbabwe)," he told mourners at the funeral of a senior army officer and independence war veteran at the National Heroes Acre in Harare.

Mugabe has previously often threatened the opposition with armed resistance from war veterans who fought British rule.

The 84-year-old, in power since 1980, is intensifying his campaign of intimidation, harassment and violence against the opposition leaders and supporters.

A presidential election run-off between Mugabe and MDC leader Morgan Tsvangirai is scheduled for June 27.

Tsvangirai, along with 11 members of his presidential election campaign, was again detained by police on Saturday, MDC officials said.

The 12 were stopped at a roadblock just outside the town of Shurugwi in the south of the country, party spokesman Nqobizitha Mlilo was quoted as saying by South Africa's Sapa news agency.

They were taken to Shurugwi police station but released about three hours later, according to party officials.

"This is just total harassment. They want us to spend more time in police cells or in detention instead of meeting the people," Tsvangirai's spokesman George Sibotshiwe said.

Police have detained Tsvangirai on at least four previous occasions in the last two weeks, holding him for several hours before releasing him without explanation or charge.

On Thursday, Tsvangirai was detained twice, first in the nearby town Kwekwe and later in the nearby central city of Gweru, where he had been campaigning.

Tsvangirai's deputy, Tendai Biti, meanwhile, appeared Saturday, handcuffed and in leg irons, before a judge in Harare.

The outspoken MDC secretary general was arrested at Harare International Airport on his return Thursday after spending two months abroad in the wake of Zimbabwe's disputed general elections in March.

His whereabouts were not known a day after his arrest on Friday.

Police accuse Biti of treason - a charge that carries the death penalty on conviction - for among others allegedly illegally distributing election results.

Biti had tried to mobilize political support against the suppression of the opposition in ongoing campaigning ahead of the run-off.

MDC member of parliament Eric Matinenga, who was arrested last week, remained in police custody Saturday, with his lawyer saying he was remanded in custody until June 26.

Matinenga is accused of inciting violence in his rural constituency of Buhere, 200 kilometres south-east of Harare.

The MDC won a majority in parliamentary elections on March 29, while Tsvangirai was accorded more votes in the simultaneous presidential election, although he failed to win more than 50 per cent which he needed to avoid fighting a run-off and to be declared outright winner. (dpa)