The Economic Freedom Fighters was disappointed by some of its members who displayed placards that carried racist messages at its launch, the party said on Tuesday.
"The EFF has learned with great disappointment that some of its members displayed banners with [messages] that seek to portray and reduce this revolutionary movement [as] a racist organisation," the party's Gauteng spokesperson Patrick Sindane said in a statement.
According to Sindane, some of the messages read "Honeymoon is over for whites" and "To be a revolutionary you have to be inspired by hatred and bloodshed".
He said the banners were spotted during the party launch on Sunday at Nkaneng informal settlement in Marikana, North West.
Thousands of supporters attended the launch at the place where police shot dead 34 people, almost all striking mineworkers, wounded 70, and arrested 250 on August 16, 2012. In the preceding week, 10 people died, including two policemen and two security guards.
"We want to put it on record that we distance ourselves from such conduct but also that we have since discovered who was behind that."
Urged to vote
"Our struggle is not to kill whites but ensure that we all equally benefit from the wealth of this country," Sindane said.
The EFF advocates the expropriation of South Africa's land without compensation, and the nationalisation of mines, banks, and other strategic sectors of the economy.
Ushered in by eight motor bikers, Julius Malema and Floyd Shivambu arrived at the Marikana koppies on Sunday for the party's launch.
Malema apologised for ever backing President Jacob Zuma, who he described as a singer who was neither a thinker nor reader.
Malema also urged all those who attended the launch of the party in Marikana to register to vote as it was the only punishment that could be given to those who killed the striking workers.
"Your vote will save lives," Malema said in reference to the Marikana massacre. "If you don't vote, those who are registered will and will put them [the ANC government] back into power."