South Africans are voting in general elections as the country marks 20 years since the end of white-minority rule.
The African National Congress (ANC) is tipped to win, returning President Jacob Zuma for a second five-year term.
These are the first elections since the death in December of Nelson Mandela, the country's first black president.
Voting has begun smoothly, with long queues and an air of excitement, especially amongst first-time voters, the BBC reports.
Those born after the end of apartheid in 1994 are casting their first national ballots.
BBC correspondents say police have been deployed to areas where there have been scene of violent protests and political tensions.
The ANC is expected to win more than 60 percent of the vote but its campaign has been hit by concern over economic problems such as high unemployment and a number of corruption scandals.
Opinion polls show there is disaffection with the country's leadership but it is not clear whether this will translate into a significant swing to either main opposition party - the Democratic Alliance, led by anti-apartheid activist Helen Zille - or the newly launched Economic Freedom Fighters, headed by former ANC youth leader Julius Malema.