Cape Town - The African National Congress says it is concerned about at what appears to be a "climate of intimidation steadily encroaching into South Africa's body politic".
In a statement released on Sunday by National Communications Manager Khusela Sangoni, the ANC noted increasing reports of political leaders, activists and journalists who had come forward with claims that they had been "intimidated by certain elements owing to their positions of beliefs".
Some had claimed to have received death threats as well.
"The ANC considers these threats in a very serious light and calls on those who have been threatened to report such to law enforcement authorities who must verify these claims and investigate. Such behaviour is an antithesis to the health and pluralistic society we seek to build where the contestation of ideas thrives," the ANC said.
"Freedom of conscience and association are inalienable rights granted to all under the Constitution. South African history is littered with violence and media suppression. Political intolerance would take South Africa back to a painful past that should not be repeated.
"Threats made against individuals because of their political or ideological beliefs is indicative of intellectual and moral bankruptcy.
"Those who plot in dark corners and make anonymous threats, as well and other forms of intimidation of others, should pursue principled and legitimate forms of engagement instead of resorting to cowardly acts.
The ANC called on South Africans to "unite behind our common vision of a pluralistic society and jealously guard our hard won freedoms - including freedom of speech and association".