They also demanded the destruction of the state's rhino horn stockpiles, in a petition delivered to the presidency in Pretoria on Wednesday.

Director of the non-profit body Section 24, Marianne du Plessis, said concern over the unabated killing of rhinos was spreading beyond South African borders.

"Not only us, the people represented here, the international community is deeply concerned with the ongoing killing of our animals," she told reporters.

"The concern also centres around our government's lack of a strong will to stop the problem."

The activists burnt a model wooden rhino horn at the Union Buildings as a symbolic act of urging government to destroy its horn stockpiles, a move they say would save the endangered rhino.