JOHANNESBURG, South Africa (AP) _ An explosion ripped through a crowded wedding celebration, killing six people and injuring 12 in an area riddled with black factional fighting, police said Sunday.

Police said they believed a hand grenade caused the blast at a wedding party Saturday night in Umbumbulu, a black towship outside Durban near the country's southeast coast.

It was unclear whether the attack was linked to the ongoing feud between the African National Congress and the Inkatha Freedom Party, the two leading black opposition groups. The ANC and Inkatha have been fighting for supremacy in the area for several years.

Elsewhere, a local ANC official was gunned down Saturday night in the huge Soweto township outside Johannesburg. Basil Zuma was killed when he refused to hand over his car keys to the assailants, the ANC and police said.

The ANC said they suspected the killing was politically motivated, while police said they were still investigating.

About 5,000 blacks have died in political violence in the past two years. Most of the deaths have been linked to the ANC-Inkatha dispute.