He said the court also charged the two with crimen injuria, a charge in South Africa that often refers to racial insult.
A new hearing was set for April 14.
Crowds of white Terreblanche supporters had gathered outside the hearing, where they clashed with groups of black protesters.
"We are celebrating the death of the man who has abused us so much," the Associated Press news agency quoted one woman in the crowd as saying.
Police erected a barbed wire barricade to separate a crowd of 200 supporters of Terreblanche's Afrikaner Resistance Movement (AWB) from a group of black workers outside the court in Ventersdorp, 100km west of Johannesburg.
AWB loyalists had been singing South Africa's apartheid-era national anthem, prompting the opposing side to respond with Nkosi Sikelel iAfrica (God Bless Africa), the anthem introduced after the country's first multi-racial elections in 1994.
South African leaders, including Jacob Zuma, the country's president, have urged calm since Saturday's killing, and police reacted quickly to separate the two groups when a white woman threw a bottle of water, a Reuters reporter at the scene said.
Police have said they believe Terreblanche, who had pushed to preserve white minority rule in the 1990s, was killed over a pay dispute.
But members of the AWB say he was hacked to death with machetes in a politically motivated attack.
The killing has exposed the racial divide that remains 16 years after the end of apartheid.
A 68-year-old woman who did not wish to be named said: "Whites still have all the power here. Since 1994, we have a black president but nothing has changed. What those men did to Terreblanche will show other farmers that we will not be oppressed."
The AWB said it would avenge Terreblache's death, only to issue an apparent retraction later.
||Terreblanche was born on a farm in the conservative Transvaal town of Ventersdorp on January 31, 1941
||He founded the AWB alongside six others in 1972 as a shadowy group seeking to protect the rights of the Boers' descendants
||In 1998, Terreblanche accepted "political and moral responsibility" before South Africa's Truth and Reconciliation Commission for a bombing campaign to disrupt the 1994 elections in which 21 people were killed and hundreds injured
However, Andre Visagie, the group's secretary-general, said on Tuesday that the decision to withdraw the threat was a mistake.
"The retraction was incorrectly reported," he told Al Jazeera from Kimberley in South Africa.
"The reason we cannot retract is because we cannot let our leader to be ... killed and have two people in jail after more than 3,000 white people have been killed on farms by black people over the past 14 years."
Visagie said the call for revenge is not a call for crime.
"We are not talking about crimes. I am talking about the fact that we see the murder as a declaration of war by the black South Africans," he said.
Terreblanche's killing has heightened a sense among AWB supporters that they are being targeted by the African National Congress (ANC), the party of Nelson Mandela that has ruled South Africa since 1994.
Julius Malema, leader of the ANC Youth League, caused controversy last month when he sang a black liberation struggle song that includes the words "Kill the Boer" - now banned by the courts as hate speech.
"Before the 1994 elections, I was afraid and thought there was no place for an Afrikaner in a black country," said Sarie Visser, a 73-year-old dressed in combat fatigues and bearing the AWB's swastika-like symbol on her armbands.
"Mandela assured us and made us feel better, but the government has changed now. If Malema cannot be stopped, we know where we stand."