"News coming out of Zimbabwe this past week is truly shocking," says the International Programme Director of Langham Preaching, a division of John Stott's ministry Langham Partnership.

In an "urgent" request for prayer, Jonathan Lamb said that ministry partners in Zimbabwe had sent messages to Langham this week urging prayer ahead of the presidential run-off elections on Friday.

"After years of economic collapse, political repression and intimidation, and greatly reduced life-expectancy, Zimbabwe is confronting yet more horrific suffering," he said.

"The new wave of terror, in advance of the presidential elections this week, is unprecedented.

"Christians in Harare say that there is one word on the manifesto of this election campaign: it is the word 'fear'."

Lamb said that in rural areas villagers are being forced to flee and live in the bush for fear of being beaten or raped. In the cities, meanwhile, supporters of President Robert Mugabe's Zanu-PF party are beating up people or forcing them to chant pro-Zanu slogans.

One pastor who wrote to Langham said that churches had been prevented from distributing food, and that more and more people were coming to the church to escape the political violence, including torture, abductions and killings.

"The wickedness is unbelievable, the lack of concern for struggling people is demonic, the deafness of those in power to the cries of the suffering and the commitment to self-advancement at the expense of others are hard to believe," the pastor wrote.

The 15-member UN Security Council issued a non-binding statement on Tuesday unanimously condemning the "campaign of violence and the restrictions on the political opposition", which it said had made the prospect of a free and fair election "impossible". Meanwhile, leader of the opposition, Morgan Tsvangirai remains at the Dutch Embassy where he sought refuge after pulling out of the election race.

Jacob Zuma, leader of South Africa's African National Congress, urged southern African leaders and the UN to intervene.

"The situation in Zimbabwe has gone out of hand, out of control...We cannot agree with what (the ruling) ZANU-PF is doing at this point in time," he told an investment conference.