United Nations officials say U.N. Special Envoy Haile Menkerios has held talks with Zimbabwean President Robert Mugabe amid international concern over widespread violence and intimidation of opposition supporters ahead of next's week runoff presidential election.  Delia Robertson reports from our southern Africa bureau in Johannesburg.

Halie Menkerios, right, UN Assistant Secretary General for Political Affairs greets Zimbabwe's President Robert Mugabe in Harare, 17 June 2008

The visit by United Nations Special Envoy Haile Menkerios comes amidst a rapidly deteriorating economic, social and political crisis in Zimbabwe including widespread violence in which some 60 opposition leaders have been killed, and dozens arrested.

Independent humanitarian organizations also report that hundreds of opposition supporters have been severely wounded and that punitive attacks perpetrated by ruling party youth and security forces have left some 25,000 people displaced. 

Opposition Movement for Democratic Change Secretary General Tendai Biti is currently in jail with the police saying he will be charged with treason.  Party leader Morgan Tsvangirai has been arrested and released without charge five times.

Humanitarian workers say that there have been very few cases of retaliatory violence on the part of opposition supporters. But Mr. Mugabe says he holds the opposition responsible for the deteriorating situation and that he intends to make them pay.

"We are going to accuse the [MDC] party and the party leadership of being vicariously liable and responsible for those crimes of violence, because there is now a pattern visible across the country and that has to stop," he said.

Morgan Tsvangirai gets off his campaign bus in Harare, 11 Jun 2008

There has been increasingly defiant rhetoric from Mr. Mugabe and his supporters, including his wife Grace Mugabe, that even if opposition leader Tsvangirai wins the runoff, they will never allow him to take power.

Speaking at an election rally this weekend, Mr. Mugabe threatened to go to war to prevent such an eventuality, and made it clear he intends to thwart the democratic process.  He told supporters that he had no intention of giving up power for what he called a "mere X" on a ballot - and asked how a ballpoint pen could fight a gun. 

U.N. representative Menkerios will remain in Zimbabwe until the end of the week.