The South African Press Association today said one of the peacekeepers was seriously hurt when armed fighters attacked the soldiers' base.
South African has contributed troops toward a United Nations military mission that is working to stabilise Congo's highly volatile east.
The mission has the strongest mandate yet of any peacekeeping effort there, allowing the peacekeepers to directly engage with the militants.
It was not immediately clear which of the many armed groups operating in the area was responsible for the attack Wednesday.
SAPA says the UN mission launched a counterattack supported by helicopters.