Security officials shot dead a man outside anti-apartheid icon Nelson Mandela's Cape Town home.
National police spokesman Mr Selby Bokaba said three men approached security officials shortly after 5 p.m. asking if the home was the residence of Anglican Archbishop Desmond Tutu.
The men demanded to speak to either Dr Tutu or Mr Mandela claiming they had information about plans to disrupt the upcoming elections.
One of the men later returned brandishing a rifle.
"He tried to cock the rifle and aimed it at the officials standing at the gate, opening fire at them. The officials returned fire and the man was shot dead," Mr Bokaba said.
Police arrested the dead man's two companions, he said.
The 85-year-old former South African president was at his Johannesburg home at the time and the motive for the attack was not known.
South Africans go to the polls for national elections on April 14th.