Under a harsh sun in a desolate corner of the South African bush, right-wing whites from a small but growing movement today rededicated themselves to saving their besieged nation from the twin perils they most fear: racial integration and black-majority rule.

Meanwhile, four more blacks, including a 3-week-old infant, were reported killed in incidents of political unrest outside the port city of Durban. Three died in attacks by other blacks, while a fourth was shot to death by police.

Several thousand whites gathered here for prayers, songs and a historical pageant recounting the sufferings and triumphs of the Afrikaners, who make up 60 percent of the white minority and who rule this country. There were also speeches warning that they face their greatest challenge not just from blacks seeking political power but from a white government too blind to see that its program of limited "reform" is the first step toward disaster.

"What we are undergoing is the darkest hour of our nation's existence," warned Carel Boshoff, a Dutch Reformed theologian and son-in-law of a late prime minister, who is the guiding light behind this movement, known as the Afrikaner Volkswag or People's Sentinel. "Like 150 years ago, the Afrikaners are seeing again how their peaceful and safe existence is being threatened, how their freedom is coming into danger and how black domination is coming closer by the day."

Mossie van den Berg, another Dutch Reformed minister, invoked the Old Testament in comparing the government to the Israelites who turned away from their God to worship idols. "God helped their enemies," he warned. If God helped Afrikaners take this land from the black tribes who once ruled it, van den Berg argued, then clearly God believes they should keep it.

This was Paul Kruger Day, a national holiday in which Afrikaners honor their George Washington, the man who defiantly led the Boer War against British imperialism at the turn of the century and died in exile after his defeat. For these whites, who have long deemed themselves a chosen people, it was a day to celebrate the apartheid system of white domination that they believe is essential to their privileges and survival.

It was also a day of recommitment. Participants signed a "covenant" pledging to preserve apartheid in the form of a white fatherland, "Christian national education" and "economic independence," in the face of an "onslaught" from black radicals, foreign critics, the press and the government itself.

Boshoff and the rightist reaction he symbolizes remain a minority among whites, with the splinter Conservative Party holding only 18 of the country's 178 white parliamentary seats. But their appeal is clearly growing as white anxieties increase following a year of escalating black unrest and continued recession. Afrikaner political scientist Willem Kleynhans, who was here today as an observer, said he believes rightist support may be approaching 50 percent of Afrikanerdom.

Part of the appeal is the right's ability to wield historic symbols that the ruling Nationalists once monopolized. Recognizing this, government officials denied Boshoff use of any of the three major Afrikaner public monuments for today's pageant, saying his purpose was overtly political. Instead the faithful were banished to this rocky, overgrown hillside 25 miles west of Pretoria.

South African President Pieter W. Botha, a despised figure among this crowd, himself invoked Afrikaner history today in a speech in the town of Delareyville, more than 100 miles west of here, reminding his audience that 13,000 blacks perished along with 28,000 Afrikaner men, women and children, in British concentration camps during the Boer War.

Botha appealed for unity and urged Afrikaners "not to despair and give up." He said, "Godless communists and their supporters are on our borders, and they will not distinguish among us."

More than 700 blacks have died in the past 14 months of unrest in South Africa, about two-thirds of whom were killed by police. The rest died at the hands of other blacks, according to official estimates.