VENTERSDORP, South Africa — Followers of one of South Africa’s most notorious white supremacists cast his death as a rallying point for their cause Sunday, with one top member claiming his brutal death was “a declaration of war” by blacks against whites.

Eugene Terreblanche’s supporters blamed his slaying on a ruling party official’s performances of an apartheid-era song that advocates killing white farmers. Police, however, say it appeared to be a wage dispute that led two of Terreblanche’s farm workers to bludgeon him in his bed Saturday.

South African officials are trying to ward off any rise in racial tensions 10 weeks before their country of about 50 million enters the global spotlight as host of soccer’s World Cup. President Jacob Zuma appealed for calm following “this terrible deed” and asked South Africans “not to allow agent provocateurs to take advantage of this situation by inciting or fueling racial hatred.”

Police Minister Nathi Mthetwa said Terreblanche was attacked by a 28-year-old man and a 15-year-old boy, both black. Mthetwa said they were arrested and would appear in court Tuesday on murder charges.

Terreblanche, a bearded, charismatic 69-year-old, co-founded and led the Afrikaner Weerstandsbeweging movement, better known as the AWB, which seeks an all-white republic within mostly black South Africa. Its red, white and black insignia resembles a Nazi swastika, but with three prongs instead of four.

Terreblanche emerged in the 1970s to the right of South Africa’s apartheid government, and had threatened to take the country by force if white rule ended. He was known to arrive at meetings on horseback flanked by masked bodyguards dressed in khaki or black.

After serving six years in prison for attacking two black workers, he re-emerged in 2004 with renewed vigor for his cause. He lived in relative obscurity in recent years on his farm outside Ventersdorp, about 68 miles northwest of Johannesburg.

Andre Visagie, a top AWB member, said Terreblanche’s face had been bludgeoned beyond recognition. He said his group would avenge Terreblanche’s death, but he gave no details.

“The death of Mr. Terreblanche is a declaration of war by the black community of South Africa to the white community that has been killed for 10 years on end,” Visagie said.

He also said the group will urge soccer teams to avoid the World Cup out of safety concerns.

Visagie would not say how many people belong to the AWB. At the height of its influence in the early 1990s, it was believed to have no more than 70,000 members.

Visagie echoed other members of the group in blaming African National Congress Youth Leader Julius Malema, saying he spread hate speech that led to Terreblanche’s killing.

Malema incited controversy last month when he led college students in a song that includes the lyrics “shoot the Boer.” Boer means white farmers in Afrikaans, the language of descendants of early Dutch settlers, or Afrikaners, and is often a derogatory term.

The song sparked a legal battle in which the ruling ANC party challenged a high court that ruled the lyrics as unconstitutional. The ANC insists the song is a valuable part of its cultural heritage and that the lyrics — which also refer to the farmers as thieves and rapists — are not intended literally and are therefore not hate speech.

“The black community has never declared war on any other nationality in South Africa,” ANC spokesman Jackson Mthembu said Sunday. “It is in fact incorrect and these are sentiments that fuel polarization of the South African populace.”