Gunmen with AK-47 assault rifles opened fire and threw grenades at a crowded funeral vigil for a member of the African National Congress Saturday, killing 35 people and wounding dozens of others, police said.

The attackers "fired indiscriminately at their victims in the open and through the tent walls" after arriving in a vehicle near the tent camp where the vigil was being held, police spokesman Col. Johan Mostert said.Police said they found corpses next to beds, draped across tent poles, and in ditches in the black Transvaal province township of Sebokeng, south of Johannesburg.

"This is certainly the most serious, the worst, single incident of black-on-black violence in an urban area that we know of," Mostert said.

"Many of those shot were children, some very young," said Daniel Douglas, a spokesman for Sebokeng Hospital, where about 40 gunshot victims were treated.

Another 16 people were injured and one killed during overnight gunbattles between residents in the Cape township of Khayelitsha, near Cape Town, police said.

The Sebokeng attack was launched "by an unknown number of black gunmen," who all apparently escaped, Mostert said.

"Little rivers of blood were going out of the tents," said Magubane Ncube, who witnessed the massacre. "People were walking around like ghosts."

"The screaming was terrible . . . those men kept shooting," said another witness, Dora Nkuni.

About 300 people attended the vigil, which was held to honor a member of the African National Congress who was kidnapped and killed in earlier factional violence, ANC spokeswoman Gill Marcus said.

The ANC was "horrified" at the attack, she said. Law and Order Minister Adriaan Vlok was also "horrified and shocked to hear the news, " according to ministry spokesman Capt. Craig Kotze.

Sebokeng has been a major flashpoint during the surge of black-on-black fighting that has killed as many as 1,000 people in townships of Johannesburg since flaring in August last year.

The Zulu-based Inkatha movement has been battling the predominantly Xhosa ANC over political and tribal differences.

Marcus said the Sebokeng community was warned before the vigil that an attack might take place.