Thirty-four people were killed after police opened fire on striking miners at a South African mine last week, the police chief has said.
Riah Phiyega said police had been forced to shoot after armed protesters charged them, "firing shots", at the Marikana mine in the north-east.
At least 78 people were injured in the confrontation, she added.
Unions are demanding an inquiry into the incident - one of the bloodiest police operations since apartheid.
The Lonmin-owned platinum mine has been at the centre of a violent pay dispute, exacerbated by tensions between two rival trade unions.
Violence had already killed 10 people, including two police officers, since the strike began a week ago.
This strike was sparked by a demand for better wages. And - armed with spears and machetes - strikers were in no mood for compromise.
But it goes much deeper than that. The traditional union in the area, the NUM, is a key ally of the African National Congress. Their backing is critical for President Jacob Zuma in his fight to retain his position in the ANC's party elections this December.
Miners accuse their leaders of abandoning their grassroots concerns, focussing instead on politics. So they turned to an alternative union to fight their corner. But - as so often happens in South Africa - this dispute turned violent. Two police had been killed earlier in the week.
The 3,000 police who surrounded the hilltop on which a similar number of miners had gathered were determined not to join their dead comrades. It is in the culture of the force. As one former police commissioner said, they should "shoot to kill" without worrying about what happened after that.
South African commentators are comparing this tragedy to Sharpeville - when the police fired at a crowd in 1960 - leading to the start of the armed struggle against white minority rule. This comparison seems a step too far. But the country is facing the bleakest moment since the end of apartheid.
Some of the strikers' wives gathered near the mine on Friday, chanting anti-police songs and demanding to know what had happened to their husbands.
"Police, stop shooting our husbands and sons," read a banner carried by the women. South African President Jacob Zuma cut short a trip to Mozambique in order to visit the mine, which lies about 100km (62 miles) north-west of Johannesburg.