Local residents have clashed with protesters at Clifton's Fourth Beach where a sheep was slaughtered on Friday evening.
Lobby group Black People's National Crisis Committee arranged the protest march following reports that private security company PPA Security allegedly closed down the beach at sunset last Sunday.
The group also held a cleansing ceremony calling for the end of the exclusion of black people at the beach.
"The offering of the sheep is calling on our ancestors to respond to our trauma at the hands of white people over the years," activist Chumani Maxwele told News24 on Thursday.
As members of the group prepared to slaughter the animal, residents tried to stop them, saying no permits had been granted for the slaughter.
The security company denied claims that its guards closed down the beach, stating that they were accompanying City of Cape Town law enforcement officers after two teenage girls were allegedly raped.
"We were requested to accompany law enforcement as our tactical officers are highly trained and skilled professionals. If anyone claims they were on the beach and chased away they would have seen that it was absolute mayhem and that law enforcement were really doing a great job to stabilise the situation - we did not close the beach," PPA CEO Alwyn Landman told News24.
In a statement issued on Friday, Cape Town Mayor Dan Plato said the security company "had no authority to ask anyone to leave", but noted that the guards had asked people of all races to leave, and did not single out any race groups.
Western Cape police confirmed that they were investigating reports of an incident of attempted sexual assault in the vicinity of Clifton Beach, in which beachgoers apparently intervened.
Police spokesperson Brigadier Novela Potelwa said police had also launched an investigation into reported claims that two teenagers had been raped on the beach on December 22.
This was the day before PPA was accused of asking people to leave Clifton Fourth Beach, at around 20:00.
"Preliminary findings of the SAPS investigation indicate that no rape was registered at Camps Bay SAPS. The police station services Clifton and Camps Bay beaches," said Potelwa.
However, she said police had information suggesting there had been an attempt to sexually assault a 15-year-old girl, which was prevented by beachgoers who reported the incident to police.
"The victim and her family refused to open a case against the suspect who is known to them," Potelwa said.