Tension is reported to be high in Zimbabwe after police banned rallies to mark the first anniversary of the controversial urban renewal campaign.
Some 500 people gathered in the city of Bulawayo amid reports that a march was given a last-minute go-ahead.
In Harare, all public rallies remain banned as the capital is holding a key parliamentary by-election.
The government's campaign, during which slums were cleared, left hundreds of thousands of people homeless.
The crowds gathered in Bulawayo were to attend a march and prayers, Ray Motsi of the Zimbabwe Christian Alliance (ZCA) told South Africa's Independent Online.
Mr Motsi said the rally in Zimbabwe's second largest city - initially banned by police - was allowed by the country's high court on Friday.
He said the march would be shorter than its organisers initially planned, adding that there was a heavy police presence in the city.
The ZCA is planning to hold prayer meetings for the victims of the urban renewal campaign across the country.
Under tough security laws, the police must give permission for all demonstrations, and protests by groups not allied to the governing Zanu-PF party are rarely authorised.
On Thursday, police arrested about 100 people marking the anniversary of last year's slum clearance programme, in which the UN says some 700,000 people lost either their homes or their jobs.