South Africa was at the centre of a new bid Tuesday to mediate between Zimbabwe's ruling party and opposition as more violence flared in the run-up to this month's presidential election run-off.

As the UN Security Council prepared for a special debate on Zimbabwe, South Africa's Business Day newspaper reported that representatives of President Robert Mugabe and his opposition challenger had recently gathered in Pretoria as part of a last-ditch effort to draw the country back from the abyss.

According to the newspaper, South African Local Government Minister Sydney Mufamadi chaired a meeting between representatives of the opposition Movement for Democratic Change and Mugabe's Zanu-PF party at the end of May and another was planned this week.

Kenya-style govt suggested

The newspaper said Mufamadi, assisted by director-general in the presidency Frank Chikane and President Thabo Mbeki's legal advisor Mojanku Gumbi, met the parties separately to discuss the 27 June run-off, including the possibility of shelving the ballot.

Among the suggestions put forward at the talks was the establishment of a Kenya-style government of national unity with Mugabe as president and MDC leader Morgan Tsvangirai as prime minister.

Disputed elections in Kenya led to violence in that country, only resolved when the ruling party and opposition formed a coalition government.

The idea of a unity government received strong backing on Tuesday from Zimbabwe's ex-finance minister Simba Makoni who finished third in the election's first round.

Makoni said the run-off should be canceled and talks should be held to form a transitional government that would be in place for five years to give it time to carry out reforms.

"Impossible to hold a fair run-off"

He said political violence had made it impossible to hold a fair run-off and pointed out that Zimbabwe, which is facing major food shortages and the world's highest inflation rate, could not afford to organise another vote.

"In the current situation, there is no hope that a free and fair election can be undertaken," Makoni, who split from Zanu-PF to run as an independent, told reporters in Johannesburg.

He refused to comment on whether reforms could happen with Mugabe at the top of a unity government.

Mbeki was last year handed the task by his peers in the region of mediating between the MDC and Zanu-PF. His efforts have so far made little headway and Tsvangirai has called for him to be stripped of his role.

However, the Business Day report said two of Tsvangirai's key lieutenants, MDC secretary general Tendai Biti and deputy treasurer Elton Mangoma, attended the meetings in the capital Pretoria.

Zanu-PF was reportedly represented by Justice Minister Patrick Chinamasa and Social Welfare Minister Nicholas Goche.

Mbeki's spokesman Mukoni Ratshitanga confirmed that talks, but refused to give further details.

MDC denies talk of talks

However MDC spokesperson Nelson Chamisa denied that any such talks had taken place, saying there "is no unity government on the cards."

Violence has increased ahead of the run-off which Tsvangirai is hoping will end Mugabe's 28-year rule of the former British colony.

According to the MDC, more than 60 of its supporters have been killed by pro-Mugabe militias since the first round of voting on March 29.

Mugabe has accused the MDC of "terrorising" Zanu-PF followers, although the UN says the vast majority of victims have in fact been opposition supporters.

In the latest reported violence, the MDC accused Zanu-PF militants of stoning an opposition senator's home and torching his car and burning two lorries of a businessman believed to be an MDC sympathiser.

Meanwhile state media reported that a veteran of the 1970s liberation war was killed and four Zanu-PF supporters injured by MDC followers in the southern Bikita region over the weekend when they were set on by axe-wielding MDC followers.

The government announced on Monday that suspected perpetrators or instigators of violence would be refused bail.

The vast majority of those arrested over the violence have been MDC supporters, including four lawmakers.

In a bid to create more room in the country's prisons, Chinamasa told the state-run Herald daily that some inmates would be freed to accommodate an expected upsurge in numbers.