Kingdom Mabuza and Sapa
Political parties have called on police to hunt down and arrest "racist anarchists" who removed a street sign for Nelson Mandela Avenue in Potchefstroom and replaced it with one reading Dela Rylaan.
The Mandela sign was dumped in the Vaal River.
Municipal spokesman Kaizer Mohau said another sign for Nelson Mandela Rylaan had been defaced to read "Dela Rylaan", an apparent reference to the Boer War general Koos de la Rey.
"About 60percent of new progressive street names have been removed in the past few months," Mohau said.
Mudini Maivha, a spokesman for the PAC, said the democratic government had to drive transformation with passion.
"Name changes are unavoidable and racist attitudes should not be tolerated. The law must deal severely with elements bent on reversing our gains," Maivha said.
Dan Habedi, secretary-general of Azapo, said it was unfortunate that racist elements who had oppressed blacks "are becoming cheeky".
ANC spokesman Tiyani Rikhotso said he expected law enforcement agencies to deal with the perpetrators.
Mohau said these actions were aimed at causing "political and social instability" and would not be tolerated.
He said 15 to 20 new street signs had been dumped in the Vaal River.
"We cannot allow a situation where people are able to do as they please when they are not satisfied with one thing or another."
Mohau said the removal of the signs had made it difficult for emergency services and the police to reach crime and accident scenes timeously.
"We trust the relevant law enforcement agencies will ensure these criminals are brought to book and that change can unfold without disturbances," he said.
Meanwhile, no decision has been made on a proposal to change the name of Potchefstroom to Tlokwe.
In March the civil society group Action Potchefstroom took the matter to court, asking for an urgent ruling to stop the city's name being changed because the public had not been sufficiently involved in the decision.
The council announced the proposed change in July.
Tlokwe is derived from the Batlhokwa people who settled in the area.
Potchefstroom was derived from the name of the Voortrekker leader Hendrik Potgieter, "chef" meaning the leader, and "stroom" from the nearby Mooi River.
The announcement last year led to protests by several opposition parties, civil society groups and the Potchefstroom campus of North West University.