Frustration and helplessness are now gripping South Africa in the wake of renewed violence over the weekend resulting in the deaths of 37 blacks - most of them in a declared unrest area swarming with security forces. People were shot or hacked to death and many were set on fire, according to police reports.

The continuing violence, particularly that of blacks killing blacks, is crippling South Africa's efforts to forge a new non-racial constitution.According to figures provided by the privately funded South African Institute of Race Relations, a total of 10,000 people have died since 1984 in township battles. The toll has been running around 200 a month during the first three months of 1991.

Since the beginning of April, clashes between Nelson Mandela's African National Congress and Mangosuthu Buthelezi's Inkatha Freedom Party have claimed another 150 lives. Officers of the ANC are convinced that there is complicity in the violence on the part of both the government and the police, even though the police have vehemently denied it.

That claim of police involvement is set forth by an ANC official in a separate column on this page.

The ANC has called for the government to take stronger steps to stop the violence, such as banning all weapons in the townships. Last week, the government banned all weapons, except spears and battle axes, on the grounds that they are "cultural weapons."

The ANC wisely thinks spears and battle axes must also be banned, while the Inkatha Freedom Party disagrees. In the meantime, the talks that are needed to chart South Africa's future are hopelessly stalled.

To make matters worse, Winnie Mandela, wife of Nelson Mandela, was found guilty this week by a South African court on charges of kidnapping and being an accessory to assaults on anti-apartheid activists at her Soweto home two years ago.

Regardless of the merits of this case, which are virtually impossible for the outside world to determine, the controversy surrounding Mandela's wife serves to seriously undermine the mantle of leadership he needs so badly to succeed in negotiations with the government.

The euphoria that greeted Nelson Mandela's release from prison last year and that seemed to portend a new era for a deeply troubled South Africa has now been swallowed up by a new chapter of inexplicable violence. Whatever its true cause, both white and black forces seem a long way from resolving it.

In addition, the black-on-black killings and tribal struggles only undermine the cause of democracy. They cannot help but make the white minority more reluctant than ever to relinquish power and to submit to what could be seen as violent and unstable black rule.