Six boys from a South African village, including one aged 10, appeared in court on Friday, charged with rape and the murder of three other children.
The group were arrested on Thursday for the August murder of three siblings: two boys and a girl aged between nine and 12 in the northern province of Limpopo.
The bodies of the three were found bound with shoelaces, said police spokesperson Brigadier Hangwani Mulaudzi.
The girl had been raped.
"The boys are charged with rape and murder, their case has been postponed till Monday," said Mulaudzi.
"Our investigation led to them. It is now up to the court to decide their case," Mulaudzi told AFP, adding that this was the most "violent and heinous" case he had seen involving children.
The boys, who are between the ages of 10 and 14, are being held in a secure location, as required by the provisions of the country's Child Protection Act.
Mulaudzi said police were still investigating if the children had been working with others.
"We have not ruled out that possibility, sadly we had to arrest these children, as much as we sympathise with them. They are suspects in a crime" he said.
South Africa's has one of the world's highest murder rates, with 42 people killed each day, according to official statistics.