Nelson Mandela said Saturday that his African National Congress is forming its own defense forces in black townships because the government has failed to stop factional fighting.

Mandela didn't say where the units would be set up or whether they would be armed.The move was a challenge to the government and the rival Inkatha Freedom Party, both of which have warned that setting up defense units would incite further violence between black factions.

A police official told the South African Broadcasting Corp. later Saturday that police opposed private armies formed by any group. Police Capt. Craig Kotze reportedly said police would not allow any group to take the law into its own hands.

Mandela's announcement came a week after the ANC demanded the government take significant steps to halt the unrest that has killed more than 6,000 people in five years. It threatened to halt talks with the government on ending apartheid if the government failed to respond satisfactorily.

Mandela said Saturday that he proposed months ago to halt talks with the government but other ANC leaders overruled him.

Speaking at a funeral rally in this squalid township, Mandela again accused the nation's security forces of encouraging the township violence to undermine the anti-apartheid movement.

The government has repeatedly denied the charge.