53 More Killed in South Africa Violence : Townships: Warring black factions stage ambushes and set fire to homes. The government appeals for international help to end the fighting.

Chaotic violence raged Wednesday through black townships, where armed gangs set fire to homes and chased people through the streets. Police said at least 53 people were killed.

It was some of the worst unrest in a month of black factional fighting in townships near Johannesburg in which more than 700 people have died.

Ambushes in Soweto, the largest black township, killed a white policeman and three blacks, while street fighting killed 46 blacks in four other townships, police said.

Worst hit was Tembisa, northeast of Johannesburg, where 25 bodies were found, police said. Also, 13 people were killed in Vosloorus, seven in Tokoza and one in Katlehong--all townships southeast of Johannesburg.

The white policeman died when the vehicle he was in was ambushed by gunmen while driving through a squatter camp in Soweto. Three other police officers were seriously injured.

The ambushed patrol went to the camp after ANC leader Walter Sisulu told them Tuesday night that members of the Inkatha movement were attacking residents, police said. Although Sisulu’s report proved false, police said their quick response showed that the force was not taking sides.

African National Congress leader Nelson Mandela and other black leaders have accused police of fueling the fighting and siding with the predominantly Zulu Inkatha movement.

Also in Soweto, three blacks died when their yellow van was riddled with gunfire from AK-47 rifles, police said. The attackers apparently mistook the van for a police vehicle, most of which are yellow.

Later in the day, police reported four black men in a van opened fire with an AK-47 assault rifle on passers-by in downtown Johannesburg, killing at least three blacks. The independent South African Press Assn. said 10 people were wounded in that attack.

Witnesses said the gunmen shot wildly at blacks waiting at taxi stands for rides to Soweto township.

In Soweto as well as in the black township of Vosloorus, police fired tear gas and birdshot to disperse crowds. Houses and cars were set on fire by the crowds, and charred corpses remained on the street in several areas.

“The Zulus are killing us,” said one man at the Tokoza squatter camp, who was carrying an ax. “Every night they come with guns.”

A resident of the Katlehong township told the South African Press Assn. that black youths attacked a train there Wednesday night, setting three cars on fire. Police said they had no report of such an attack.

Meantime, people piled possessions into wheelbarrows and supermarket carts to flee clashes between groups armed with machetes, axes, spears and clubs in the black townships.

“We have to leave. We are helpless without guns,” said one man who refused to give his name.

Mandela on Tuesday appealed for peace after emergency talks with President Frederik W. de Klerk.

On Wednesday, Foreign Minister Roelof F. (Pik) Botha appealed to the United Nations for international help to end township violence threatening to derail political reform in South Africa.

In a letter, Botha called on the United Nations to pressure Mandela and Inkatha leader Mangosuthu Buthelezi to join forces in seeking an end to the fighting. The ANC has so far rejected contact with Buthelezi.

The fighting involves Zulus loyal to the conservative Inkatha movement and Xhosas and other blacks linked to the ANC. It began Aug. 12 in Johannesburg-area townships after spreading from Natal province in the east. Natal is the traditional Zulu homeland.