"Yesterday the police were clear that today we are going to disarm them and remove them from the hill because the gathering is illegal," Xolile Mngambi, a reporter for CNN affiliate ETV, said Friday.

By Thursday afternoon, another round of negotiations among the striking miners, the unions and Lonmin had failed.

A heavily armed police Tactical Response Team moved in to disperse the miners.

To hear Phiyega, the police commissioner, describe it, the police weighed all their options and decided to fence in the miners with barbed wire -- to compartmentalize them into more manageable groups.

"The armed protesters moved toward the police," she said. "They were driven back with tear gas and rubber bullets. But when they fired, police used maximum force."

But journalists at the scene could not say whether the protesters fired first.

"We cannot say to you the police were provoked," Mngambi said.

Then, the police unleashed a barrage of gunfire. One witness said it went on for three minutes.