Morgan Tsvangirai on a "military junta"
Opposition leader Morgan Tsvangirai says Zimbabwe "is effectively being run by a military junta".
He said 66 opposition supporters had been killed in political violence since March's disputed presidential elections and 200 more were unaccounted for.
Mr Tsvangirai's Movement for Democratic Change says he beat President Robert Mugabe outright. Officials say there must be a run-off on 27 June.
Mr Tsvangirai said he would not accept a victory for Mr Mugabe in the run-off.
'Victory is certain'
BBC Southern Africa correspondent Peter Biles says this is not the first time Mr Tsvangirai has claimed that Mr Mugabe's security officials are in charge.
Our correspondent says Mr Tsvangirai has alleged that Police Commissioner Augustine Chihuri is responsible for favouring the ruling Zanu-PF party in creating a partisan culture of policing.
Robert Mugabe blames his rivals for election violence
Mr Tsvangirai said the MDC was sure to win the run-off vote and dispelled rumours of discussions about a possible unity government with Zanu-PF.
"The MDC is focused on the run-off, our victory is certain," the party leader told a news conference in the capital Harare.
"Mugabe will lose. It's just a formality to go and campaign, the people have already decided."
He added that "the issue of a government of national unity before the run-off does not arise".
He was referring to comments made earlier by the defeated third presidential candidate, Simba Makoni, who said supporters of Mr Tsvangirai and Mr Mugabe were in contact to try to resolve the crisis.
Mr Tsvangirai said a total of 3,000 MDC supporters had required hospital treatment through state-sponsored violence, with 25,000 displaced.
The New York-based Human Rights Watch organisation said on Monday that free elections were not possible because of the Zanu-PF-organised violence.
Mr Mugabe blames his rivals for the bloodshed.
The government has said those suspected of violence will now be refused bail.