Tens of thousands of chanting and dancing revelers waved the green and gold colours of the African National Congress as Africa's oldest liberation movement celebrated its 100th anniversary Sunday, though many South Africans say the party hasn't delivered on its promises since taking power in 1994.

A dozen African leaders and more former heads of state along with African kings and chieftains attended a midnight ceremony where President Jacob Zuma lit a flame, expected to stay alight the entire year, at the red brick, tin-roofed Wesleyan church where black intellectuals and activists founded the party in 1912.

Absent because of his frailty was Nelson Mandela, South Africa's first black president who is just six years younger than his movement. The world icon was jailed for 27 years by the racist white government and his organization was formerly declared a terrorist group by the United States.

'We need to ensure that our program of transforming our country is accelerated'—Jacob Zuma, president of South Africa

Joy at the ANC's leading role in ending white minority rule in 1994 was tinged with sadness over its failure to bring a better life to most South Africans, and corruption scandals that have embroiled its members in recent years.

The 45,000-seat stadium in Bloemfontein, located 400 kilometres southwest of Johannesburg, overflowed Sunday with crowds that spilled outside, dancing and singing under a blazing sun.

"We need to ensure that our program of transforming our country is accelerated and taken to new steps," Zuma said in an afternoon address, flanked by an aide holding an umbrella.

He acknowledged the problems confronting the ANC, saying it needs to "defeat the demon of factionalism" and to take "urgent and practical steps to restore the core values, stamp out factionalism and promote political discipline."

Thousands left the stadium during Zuma's 90-minute speech, which was devoted mainly to the history of the ANC. It was unclear if that was because of the heat, because people had to leave town due to lack of accommodation or whether they were sending Zuma a message. One woman left saying she was bored.

Deputy President Kgalema Motlanthe then proposed a toast and told the half-empty stadium that if they did not have champagne, they could take photographs of their leaders drinking, or raise clenched fists. "The leaders will now enjoy the champagne, and of course they do so on your behalf through their lips," he said.

Unemployment an issue

Zuma has said the ANC will rule "until Jesus comes" but the next few years will be critical ones for the party that has won a landslide victory in every election for the last 18 years.

The ANC describes itself as the home of the working class and the poor, but inequality has grown in recent years even as a small black elite around the party has become multimillionaires flaunting lavish lifestyles.

Unemployment hovers around 36 per cent and soars to 70 per cent among young people. Half the country's population lives on just 8 per cent of the national income, according to the Congress of South African Trade Unions.

A warning sign came from the town of Clarens, where stone-throwing protesters smashed the windows of a bus that was to transport supporters to the centenary celebrations in Bloemfontein, 260 kilometres away.

Protesters, demanding ANC municipal leaders be fired for failing to deliver basic services like tap water, stoned vehicles and blocked the road to Bloemfontein, Talk Radio 702 reported.

Such protests have become daily events across the country, where political liberation has not been matched by economic emancipation as Africa's largest economy remains in the control of the white minority.