Cyril Ramaphosa, the deputy president of the ANC, was heckled and booed during a lecture on the National Development Plan (NDP) on Tuesday.
A member of the Marikana Support Campaign stood at the foot of the University of the Witwatersrand's Great Hall stage during a question and answer session with Ramaphosa and screamed at him.
“How do you sleep at night? You have blood on your hands,” the woman cried.
As university security guards led the woman out of the hall, she could still be heard shouting.
Ramaphosa was also disrupted in his speech after the campaign group began shaking their placards while he was speaking.
“I want to pause and ask those who are shaking the papers to be respectful to other people who do not have paper in their hands,” he said.
“It cannot be right that when the vice-chancellor allowed us all in here, he extracted an agreement from all of us and the agreement is to respect each other's right to speak.”
Several members of the audience used the question and answer sessions to level criticisms at Ramaphosa and the NDP.
One man criticised Ramaphosa, saying that the election of one of the richest people in the country as deputy president of the African National Congress was worrying.
“The NDP is old wine in new bottles, and that's what we are asking for,” he said sarcastically.
“We are asking for more Marikanas, more shooting, more inequality, more brutality and less service delivery.”
Earlier, Marikana Support Campaign members sang and danced in the hall.
The group sang against capitalism and held up posters saying: “Don't let the politicians get away with murder.”
Thirty-four people were shot dead, almost all of them striking mineworkers, on August 16, 2012, while police were trying to disperse them at Lonmin's Marikana mine.
Ten people, including two policemen and two security officers, were killed in the preceding week.
Ramaphosa, a former board member at Lonmin, was criticised for calling for action against the mineworkers before the shooting.
Ramaphosa said there were appropriate platforms for Marikana to be discussed.
“I can assure you that many people feel the pain of the people who continue to suffer as a result of Marikana, which is deeply regretted.”
Ramaphosa, who also serves as the deputy chair of the national planning commission, discussed the economic advantages of the NDP.
He said it was a plan that could deliver faster and inclusive economic growth in South Africa.
“It is only natural for economic policy to be amongst the most contested terrains,” he said.
“It (the NDP) is contested, with different approaches to how we should grow our economy. We are a nation after all, of people who love to talk... and that is good.”
He said the Constitution allowed freedom of speech.
When Ramaphosa said that striking workers had greater protection since 1994, a member of the audience shouted: “They now get shot instead.”
Sapa