Pressure mounted on Zimbabwe on Friday to admit foreign observers to oversee a presidential election run-off amid fresh claims that pro-government militias are deliberately instilling terror.

The opposition said 30 supporters had now been killed and a union chief said 40 000 farm workers and their dependents had been made homeless, although authorities played down the levels of violence.

Six days since results from an inconclusive 29 March poll were announced, there was still no word on when a second round would take place nor whether the opposition Movement for Democratic Change (MDC) would participate.

Its leader Morgan Tsvangirai has argued that President Robert Mugabe, who lost the first round but not by a sufficient margin for the MDC to avoid a run-off, is trying to spread fear to cling on to power.

In its latest death toll, the MDC said it now had information 30 supporters had been killed by Mugabe supporters in attacks in rural areas.

"What is worrying is that each day comes with gory stories of how human beings are being treated," said spokesperson Nelson Chamisa.

"This is why we are appealing on bended knees to the international community to assist in ending the carnage."

President Mbeki to meet leaders

South African President Thabo Mbeki was expected in Zimbabwe on Friday to hold talks with political leaders, a foreign affairs spokesman said — without specifying if that included opposition leader Tsvangirai.

"In Zimbabwe, he is going to meet the political leadership of that country...all the political leaders in that country," Ronnie Mamoepa told AFP on Thursday.

"Mbeki will meet with the country's political leadership in the context of his Southern African Development Community (Sadc)-mandated facilitation process," said Mamoepa, quoted by South Africa's SAPA news agency.

But George Sibotshiwe, a Tsvangirai spokesperson, told AFP that the MDC had not been officially informed that Mbeki would meet with his party.

Regional leaders last month in Lusaka called on Mbeki to continue his mission as chief mediator between Zimbabwe's ruling Zanu-PF party and the opposition following recent disputed elections.

The MDC has, however, asked for him to be removed by the Sadc regional bloc as mediator.

The leader of a Zimbabwe farmworkers' union told a press conference in South Africa that 40 000 people had been driven off their land since 29 March either as a result of direct attacks by militias or through fear.

"They have been accused of voting for the opposition. Most of them are either on the roadside or sheltering at some farms," said Gertrude Hambira, general secretary of the General Agriculture and Plantation Workers Union of Zimbabwe.

Hambira said militias were targeting rural areas, traditional strongholds for Mugabe where he did worse than expected on polling day.

Growing international concern

International disquiet, however, is growing, with UN chief Ban Ki-Moon calling for international observers to oversee the run-off and the White House pressuring Mugabe and his supporters to put an end to the violence.

In a statement, Ban said "future stages of the electoral process must be conducted in a peaceful, credible and transparent manner in the presence of international observers" while also voicing concern about violence.

US national security council spokesperson Gordon Johndroe said Mugabe and his supporters needed "to refrain from (violence and intimidation) against those who are supporting the opposition."

Gordon Brown, prime minister of former colonial power Britain, echoed the calls for overseas scrutiny.

The run-off should in theory take place on 24 May, but the electoral commission has indicated the deadline will be missed and the head of a South African observer mission has said the country is too violent to hold an election.

Mugabe, at 84 Africa's oldest leader, has been in power since independence from Britain in 1980.

Once seen as a post-colonial success story, Zimbabwe has been in economic meltdown since 2000 when Mugabe embarked on a programme of land reforms which saw thousands of white-owned farms expropriated.

Inflation now stands at over 165 000 percent and unemployment is above 80 percent, while around a third of the 13 million population has left the country.

AFP