A crowd of several hundred gathered in Nairobi National Park on Saturday to watch Kenyan President Uhuru Kenyatta set fire to 105 tons of elephant tusks and more than a ton of rhino horn, dpa reported. The crowd, among them leaders of other African nations, stood in silence as they watched the pyres of ivory, valued at around 150 million dollars, go up in smoke. It was the first such burning to take place since 1989 - part of Kenya's desperate battle against poachers. According to the African Wildlife Foundation (AWF), some 35,000 tuskers were killed in Africa last year, out of a total African elephant population of between 400,000 and 500,000. The situation is even worse for rhinos. Since 1960, almost 98 per cent of the continent's black rhinos - the hook-lipped rhino - have been killed. A kilogram of elephant ivory is worth around 1,100 dollars on the black market, according to the organization Pro Wildlife. Rhino horn goes for 50 times that figure, with China being the main market. Nature conservation organizations have voiced their support for the destruction of these stockpiles. "Storing the confiscated tusks is laborious and expensive," says Pro Wildlife's Daniela Freyer. They also represent a risk, as poor countries could earn a great deal of money by engaging in the illegal ivory trade.