Leading article: A warning sign for the ANC

Film of the massacre at the Marikana platinum mine in South Africa last week, in which 34 protesters were shot dead by police, suggests chaotic panic among badly trained officers. But one of the leaders of the strikers insists it was planned. "The writing is on the wall, they are going to kill you," said Joseph Mathunjwa, of the Association of Mineworkers and Construction Union, just before the violence began.

However it happened, Marikana looks set to become a polarising political symbol reminiscent of the Sharpeville Massacre of anti-apartheid protesters in 1960. On one side stand the militants of the AMCU, on the other, those of its rival, the National Union of Mineworkers. But this is more than a clash between two unions. It is a conflict between the post-apartheid promise and the corrupt reality that goes to the heart of modern South Africa.

The NUM is at the centre of South Africa's union movement which, together with the South African Communist Party and the ruling elite, the African National Congress, form an alliance which has dominated the country since the end of white rule. Despite repeated pledges to improve life for ordinary citizens, in practice it has created an elite which has enriched itself through patronage. The average man or woman is little better off than before.

The choice between corruption and violence is an unhappy one. President Jacob Zuma's handling of the Marikana tragedy has dented his chances of being re-elected head of the ANC in December. Meanwhile, the extremist Julius Malema, expelled from his role as president of the ANC Youth League, is making political capital from the events, visiting the scene of the shooting and attending yesterday's memorial service to sit with widows of the dead.

The South African people are angry and the pressure on the ANC is rising inexorably. Protests have brought more than two million onto the streets every year since 2008. After more than 18 years in power, the ruling elite can no longer blame apartheid. Now it is their own moral authority being eroded. None of which augurs well for the future.