The African National Congress on Saturday accused the nation's defense forces of training ANC rivals as part of a plot to stir up black violence and improve the image of the white minority.

ANC Deputy President Nelson Mandela and Secretary-General Alfred Nzo leveled angry accusations at the government in separate speeches.Nzo told reporters at the Mandela home that the ANC had learned of a terror campaign that included plans to kill ANC leaders and was sanctioned by "sinister" elements in the defense forces.

An ANC statement accused unidentified agitators of planning the campaign to ruin a peace agreement with the ANC's rival, the Inkatha Freedom Party, in hopes of making it appear blacks are unable to govern themselves.

"Information gathered indicates there are massive plans to attack communities and assassinate prominent ANC members," Nzo said. "General mobilization is taking place for attacks in the townships, trains and factories."

The ANC did not say where its information came from or offer specific proof.

Law and Order Ministry spokesman Craig Kotze asked the ANC to provide it with details so police could investigate the claims. The ministry has denied past ANC allegations that security forces instigated unrest.

The ANC claimed on Saturday that Inkatha brigades had been deployed in violence-torn areas after receiving military training from members of the defense forces.

"A sinister hand of the third force has become apparent," the ANC said, referring to an element in the government that the ANC says wants to undermine President F.W. de Klerk's reforms dismantling apartheid. "The intention is to create, where it does not exist, and to exacerbate where it does exist, conflict between the ANC and the Inkatha Freedom Party."

A defense forces spokesman denied the allegations "with contempt" and read a statement accusing the ANC itself of planning violence and trying to shift the blame in advance. He spoke on condition of anonymity.

Amid the angry words from the ANC, the government freed 37 more political prisoners under terms of an agreement reached in August with the organization.

The group included 28 ANC members and seven members of the militant Pan Africanist Congress.

Perhaps the best-known was Marion Sparg, a white ANC member who was accused of planting mines in police stations around the country. She was sentenced to 25 years in prison in 1986.