The lieutenant opened fire on soldiers from the First South African Infantry Battalion with an assault rifle. The dead were on their way to shooting practice. The civilian who died was a woman working at the base.
The lieutenant, who had served in the South African National Defence Force for several years, was eventually shot dead by other soldiers. "He had to be shot because he would have killed more people," said a police spokeswoman.
Five other soldiers were injured in the attack on the Tempe military base in Bloemfontein in the Orange Free State. All are in hospital, one critical. That they were also white will fuel speculation about a racial motive.
The SANDF was created in 1994 at the end of white rule. It brings together white soldiers, who for decades defended apartheid, with their former enemies, members of MK, the African National Congress's guerrilla force. Unsurprisingly it has proved an uneasy union.
The first black chief of the armed forces, General Siphiwe Nyanda, was appointed in 1998 when General Georg Meiring resigned after a bizarre episode in which the SANDF claimed to have uncovered a coup plot against President Nelson Mandela. An independent commission later found the coup plot allegations to be completely "fraudulent".
Despite the appointment of blacks at the very top, former MK soldiers have complained of prejudice and protection of white privilege in the ranks. Any sense of injustice can only have grown during the programme to reduce the 100,000-strong SANDF to about 70,000.
Early last year a report by British military advisers suggested that former MK members had every reason to be dissatisfied. The advisers, overseeing the integration process, concluded that white army commanders - mainly Afrikaners - were thwarting the process and that white officers' attitudes were "hardening".
Tempe was one of the first bases to integrate former MK soldiers with the apartheid-era forces. Last summer the base was at the centre of a scandal when two soldiers, suspected of being white right-wingers, were arrested after arms and ammunition were stolen from a hijacked military lorry.
Yesterday Brigadier-General Hans Heinze, Tempe's commander, speaking on national television in Afrikaans, called for calm. "Let us allow the case to be thoroughly investigated before we draw any conclusions," he said.
Although South Africa's transition to majority rule was relatively bloodless, racial tension still runs high five years after the election to the presidency of Nelson Mandela. It has surfaced in violence between white farmers and their labourers, in schools and even in national sports teams.
But the fraught relations in the armed forces, some politicians warn, are potentially the most dangerous area of friction. Among the dead yesterday were a major and a captain.Reuse content