The Lonmin-owned platinum mine has been at the centre of a violent pay dispute, exacerbated by tensions between two rival trade unions.
The incident is one of the bloodiest police operations since apartheid. Violence had already killed 10 people, including two police officers, since the strike began a week ago.
The images, along with Reuters television footage of a phalanx of officers opening up with automatic weapons on a small group of men in blankets and t-shirts, rekindled uncomfortable memories of South Africa's racist past. After over 12 hours of official silence, police minister Nathi Mthethwa confirmed that at least 30 men had died when police moved in against 3,000 striking drill operators armed with machetes and sticks and massed on a rocky outcrop at the mine, 100 km (60 miles) northwest of Johannesburg. Some of the carnage was captured in the raw video [HERE]
In a front page editorial, the Sowetan questioned what had changed since 1994, when Nelson Mandela overturned three centuries of white domination to become South Africa's first black president. "It has happened in this country before where the apartheid regime treated black people like objects," the paper, named after South Africa's biggest black township, said. "It is continuing in a different guise now."
President Jacob Zuma cut short a visit to a regional summit in neighboring Mozambique to head to the mine. Zuma, who faces an internal leadership election in his ruling African National Congress (ANC) in December, said he was "shocked and dismayed" at the violence, but made no comment on the police behavior.
"We believe there is enough space in our democratic order for any dispute to be resolved through dialogue without any breaches of the law or violence," he said in a statement.
Despite promises of a better life for all South Africa's 50 million people, the ANC has struggled to provide basic services to millions in poor black townships. Efforts to redress the economic inequalities of apartheid have had mixed results.
The mining sector comes in for particular criticism from radical ANC factions as a bastion of "white monopoly capital".
POLICE PRESENCE
As dawn broke, hundreds of police patrolled the dusty plains around the Marikana mine, which was forced to shut down this week as a rumbling union turf war that has hit the platinum sector this year boiled over.
"There were no problems overnight. The problem is the hill over there where the shooting took place. I am not sure what will happen today," said Patience, a woman who lives in a nearby shanty town. She declined to give her full name.
Crime scene investigators combed the site of the shooting, which was cordoned off with yellow tape, collecting spent cartridges and the slain miners' bloodstained traditional weapons - machetes and spears.
Firearms were also recovered at the scene, they said, backing police reports they were shot at first.
Prior to Thursday, 10 people - including two policemen - had died in nearly a week of conflict between rival unions at what is Lonmin's flagship plant. The London-headquartered company has been forced to shut down all its South African platinum operations, which account for 12 percent of global output.
South Africa is home to 80 percent of the world's known reserves of platinum, a precious metal used in vehicle catalytic converters and for other engineering purposes. Rising power and labor costs and a steep decline this year in the price have left many mines struggling to stay afloat.
Although the striking Marikana miners were demanding huge pay hikes, the roots of the trouble lie in a challenge by the upstart Association of Mineworkers and Construction Union (AMCU) to the 25-year dominance of the National Union of Mineworkers (NUM), a close ANC ally.
"There is clearly an element in this that a key supporter of the ANC - the NUM - has come under threat from these protesting workers," said Nic Borain, an independent political analyst.
AMCU leaders have been criticized for telling the striking miners - many of whom are barely literate - that they were "prepared to die" rather than move from their protest hill.
Pre-crackdown footage of dancing miners waving machetes and licking the blades of home-made spears raised similar questions about the habitual use of violence in industrial action 18 years after the end of apartheid.
"This culture of violence and protest, it must somehow be changed," said John Robbie, a prominent Johannesburg radio host. "You can't act like a Zulu impi in an industrial dispute in this day and age," he said, using the Zulu word for armed units.
World platinum prices spiked nearly 3 percent on Thursday as the full extent of the violence became clear, and rose again on Friday to a 5-week high of $1,450 an ounce.
Lonmin shares in London and Johannesburg fell more than 5 percent to 4-year lows, bringing their losses since the violence began a week ago to nearly 20 percent.