By Nick Miles
BBC News, Johannesburg
Methodist bishops from southern Africa have warned that a potential genocide could take place in Zimbabwe.
Demolitions have left hundreds of thousands homeless
The bishops, meeting in Johannesburg, also called on South African president Thabo Mbeki to do more to help the rights of refugees leaving Zimbabwe.
The comments come six weeks after the start of mass demolitions of illegally built houses and stalls.
According to the United Nations, the destruction of shanty towns has left at least 200,000 people homeless.
The statement from the bishops was unequivocal: "We have on our hands a complete recipe for genocide; we're witnessing a tragedy of unprecedented enormity."
It's one of the strongest statements yet from church leaders in the region on the human rights situation in Zimbabwe.
It mirrors similar sentiments expressed last month by Archbishop Pius Ncube of Bulawayo, a leading critic of President Robert Mugabe.
At a meeting in Johannesburg, the Methodist bishops also called on Thabo Mbeki to do more to make it easier for people to come from Zimbabwe to claim refugee status and protect their rights.
They also criticised the South African government for its quiet diplomacy approach to Zimbabwe which has fallen short of openly criticising President Mugabe.
The bishops urged South Africa to do more for Zimbabwean refugees
The statement came as a UN special envoy, Anna Tibaijuka, continues her visit to Zimbabwe to assess the impact of the government campaign against illegal structures and informal traders.
Opposition groups there say the campaign was aimed at persecuting their supporters.
A number of political leaders, including British Prime Minister Tony Blair, have spoken out against the campaign.
But African leaders have remained silent. They consider the demolitions an internal matter for Zimbabwe.