Updated

A black farmworker was sentenced to life in prison Wednesday for the brutal murder of South African white supremacist leader Eugene Terreblanche in a case that has been a source of racial tension in the city of Ventersdorp.

About 100 protesters sang anti-white songs outside the courtroom in the city just west of Johannesburg to support 30-year-old Chris Mahlangu, who had pleaded guilty but argued that he acted in self-defense in what the judge found was a violent dispute over wages. They were opposed by 20 white protesters who carried the dummy of a black man with a rope around his neck and a sign that said: "Hang Mahlangu." As Mahlangu was leaving the court, the protesters tied the effigy to a pick-up truck and drove around the black crowd.

Mahlangu was found guilty for beating Terreblanche, 69, to death with an iron in April 2010. Mahlangu said he feels he did no wrong by ridding the world of a man some called a monster.

The judge had rejected a defense argument that Mahlangu had been sodomized by Terreblanche and acted in self-defense. Mahlangu also claimed that Terreblanche infected him with HIV.

Zola Majavu, Mahlangu's lawyer, said on Wednesday that they are planning to appeal both the court's findings and the sentence.

On Wednesday, Mahlangu said he has converted to Islam while in prison.

A second man, Patrick Ndlovu, who was a teenager at the time of the killing two years ago, was sentenced to a two-year prison sentence which means he goes free. Ndlovu was acquitted of murder but found guilty of breaking and entering with intent to steal. Initially, he was not named because of his age. He turned 18 during the trial.

After the sentencing, the Young Communist League of South Africa released a statement calling the judgment racially biased.

"Eugene Terreblanche was a white supremacist who made no qualms about his lack of love and respect for the black Africans and still believed in white supremacy and black oppression. How is it that the issue of self-defense is not taken serious?" said the statement.

Terreblanche co-founded the Afrikaner Resistance Movement, known by its Afrikaans initials as the AWB, to seek an all-white republic within South Africa.

In 1997, Terreblanche was sentenced to six years in prison for the attempted murder of a black security guard and assaulting a black gas station worker. Terreblache's influence in the white supremacist movement had waned by the time he died.