(CNN) -- Zimbabwe's opposition said post-election violence was increasing Wednesday, a day after the army denied unleashing attacks on critics in the southern African country.
Members of the main opposition party say supporters of Zimbabwe President Robert Mugabe have beaten them.
The main opposition party, Movement for Democratic Change, reported 25 supporters have been killed since the March 29 elections, and church groups said militias have killed eight people and wounded 30 others in the past two days.
The church groups didn't identify the victims, saying they needed to inform families first. The groups also said they are sending out pastors to investigate reports from human rights organizations that army barracks have been turned into torture camps.
South African President Thabo Mbeki dispatched a team this week to look in to the violence in neighboring Zimbabwe. Mbeki's office did not give any details.
Zimbabweans have yet to learn when a runoff will be held after last week's announcement of the presidential election results. The Zimbabwe Election Commission said MDC candidate Morgan Tsvangirai received more votes than incumbent Robert Mugabe but not enough to avoid a runoff.
MDC sources said the commission is unlikely to announce a date for the runoff soon, because it is trying to secure funding to hold the vote. Mugabe's Zanu-PF party could not be reached immediately for comment.
The commission delayed the release of the presidential election results for weeks amid charges that Mugabe's supporters were working to steal the race.
The official tally was announced Friday, more than a month after the election. It showed Tsvangirai won 47.9 percent of the vote, compared with 43.2 percent for Mugabe.
Under Zimbabwe law, a runoff is needed when neither candidate gets a tally of 50 percent plus one vote.
The MDC has said Tsvangirai won 50.3 percent of the vote, which would have avoided a runoff.
CNN's Nkepile Mabuse in Johannesburg, South Africa, contributed to this report.