Zimbabwe opposition won't meet with visiting mediator Mbeki

Tsvangirai's party, the Movement for Democratic Change, is expected to make an announcement Saturday in South Africa on whether it will take part in a runoff.

No date has been set for the vote, although Mugabe has already begun campaigning.

Meanwhile, opposition party supporters are increasingly under attack.

The Zimbabwe Association of Doctors for Human Rights said 22 people had died and 900 were tortured in postelection violence.

But "violence is now on such a scale that it is impossible to properly document all cases," the association said in a statement Friday, citing a "dramatic increase" in violence since the start of May.

In the last 24 hours, Harare hospitals and clinics have treated 30 people for broken limbs, the association said. Those admitted to hospitals with injuries included elderly men, breast-feeding women and a 3-year-old boy struck in the eye by a rock, it said.

"The level of brutality and callousness exhibited by the perpetrators is unprecedented," the statement said.

The doctors also raised concerns about the intimidation of health workers and a shortage of medical supplies.

Meanwhile, the deputy director of army public relations, Maj. Alois Makotore, denied accusations that soldiers had harassed or assaulted people, the state-owned Herald newspaper reported Friday.

The newspaper also accused opposition supporters of burning the homes of ruling party supporters. Government and party officials have denied they were responsible for the violence and instead blamed the opposition.