“Every member of the community has a duty to report anything suspicious they know about this shocking execution of the men,” the African National Congress’s Kraaifontein constituency office head Richard Dyantyi said in a statement.
“The brutal killings should not go unpunished.”
He said the community had to be the eyes and ears of the police.
On Thursday, police said the bodies of six unidentified men had been found near a farm in Kraaifontein.
Read more: 6 bodies found near WCape farm
Police suspected that the six, aged between 18 and 30, had been stoned to death.
Their bodies were discovered lying face down with their hands tied behind their backs, by passers-by in Joostenberg Vlakte around 10am on Tuesday.
They alerted the police. Six murder cases were opened.
Later in the day four of the six bodies had been identified. The four men were from Wallacedene.
Read more: Four bodies identified – police