The 37-year-old law barring blacks from many public facilities formally ended Monday, and the African National Congress urged blacks to counter right-wing opposition by exercising their new rights.

In another development, black factional fighting broke out in a township east of Johannesburg on Sunday night. Police said seven blacks were killed at a migrant workers hostel in fighting between rival groups armed with pistols and knives. The fighting was the worst incident after several weeks of relative calm in the black townships in the area.The lifting of the Separate Amenities Act, which was a pillar of South Africa's apartheid system, was not expected to have noticeable effects in major cities, where segregation has eased in recent years.

But in smaller towns controlled by the right-wing Conservative Party, a showdown was set between blacks and white authorities and residents opposed to the changes.

In the town of Middelburg in the Conservative-dominated Transvaal province, residents have voted to close all public facilities rather than open them to all races.

Other towns planned to charge fees higher than most blacks can afford to restrict their use of public amenities. Black leaders threatened strikes and boycotts to protest the actions.

"Entry to public facilities must be unconditional and free. What these councils are planning is an illegal act of banditry," said the ANC's secretary in the eastern Transvaal, Joe Nkuna.

He said the formation of vigilante groups to keep blacks out would fail if people were determined to end discrimination, and he appealed to blacks to begin using the amenities.

Parliament repealed the Separate Amenities Act in June and gave communities until Oct. 15 to comply. The governing National Party had approved the act in 1953, five years after it came to power on a platform advocating strict separation of the races.

Since President F.W. de Klerk took office in August 1989, however, he has instituted a number of racial reforms, released such emminent black leaders as Nelson Mandela, and begun talks with the ANC to negotiate a new constition giving the black majority some share of power.