South African President Jacob Zuma has dedicated his ANC's landslide victory in general elections to Nelson Mandela.

"We dedicate our victory to Madiba's memory," Mr Zuma said, using Mandela's clan name as a sign of respect, speaking for the first time on the ANC's election win in Wednesday's vote.

The army was deployed overnight in a township in Johannesburg to quell violence over alleged voter fraud.

Completed results showed the African National Congress won 62.15% of the ballots, while the main opposition Democratic Alliance came in second with 22.23%.

The military was deployed overnight in Johannesburg's Alexandra township after police used stun grenades and rubber bullets to disperse protesting crowds, according to police spokesman Neville Malila.

The military appeared to have left the area by this morning, according to an AFP photographer.

Authorities arrested 59 people for public violence after a crowd of up to 400 people burned tyres and barricaded streets in protest at the arrest of other rioters the day before.

The unrest reportedly follows allegations of vote-rigging in the area during Wednesday's general polls, which marked 20 years of democracy since the end of apartheid.

Military spokesmen could not be immediately reached for comment.