Two protesters died during protest action in the Caledon area in the Western Cape on Thursday morning, with IPID investigating whether it was at the hands of police officers.
National police spokesperson Vishnu Naidoo said that according to preliminary reports, police were dispersing the crowd when the two died.
It was initially understood that they had been shot by police. A Western Cape ANC source told News24 that he had received information that the protesters had been shot by police, but could not confirm this as fact.
Another source said that the two protesters died during a stampede after police fired rubber bullets.
Western Cape police spokesperson Lieutenant Colonel André Traut confirmed the deaths, but referred News24's enquiry about the two fatalities to the Independent Police Investigative Directorate (Ipid).
Ipid spokesperson Moses Dlamini told News24 that investigators are on the way to the scene. "Once we have interviewed witnesses, we'll be able to determine what happened," Dlamini said.
Police are on the scene where people are protesting about service delivery problems, Traut said by email.
At 13:15, Dennis Cruywagen of the Western Cape ANC, who had travelled to the scene, told News24 that - according to eyewitnesses he had spoken to - police fired live rounds at the protesters, and that the two deceased protesters were killed during a stampede that followed.
Community Safety MEC Alan Winde posted a photo of a Theewaterskloof Municipality letter on Twitter to indicate that the protest was illegal as a march had only been planned for Tuesday.
He told TimesLive: "It is alleged that there are political parties who are at the forefront of these protests. These parties are willing to put lives on the line to advance their agendas. I see from video footage that these instigators are using children."
The ANC's Western Cape head of election, Ebrahim Rasool, mourned the deaths and said it was not the time to accuse other political parties of instigating protest action.
"Winde wants to silence the protests actions and the protesters calls to bring attention to inadequate delivery of services to their communities, nullifying the protest by calling it illegal," he said.
National Police Commissioner, General Khehla John Sitole, called for calm and directed police officers to cooperate fully with IPID's investigation.
"The IPID is an independent institution which is mandated to conduct such investigations in an objective unbiased manner."