Poachers have killed 287 rhinos in South Africa this year, including 16 critically endangered black rhinos, the World Wildlife Fund reported Wednesday.

South Africa is home to the majority of the world's rhinos, and the 271 African white rhinos killed there this year represent 1.3% of the entire population of the animals, the conservation group said.

The rhinos are killed for their horns, which are used in traditional medicine in Asia, including a misplaced belief they can cure cancer, according to the group.

"Demand for rhino horn and elephant ivory is threatening to destroy a large part of Africa’s natural heritage. We want to see illegal markets for these products in Asia shut down for good,” Morné du Plessis, CEO of WWF-South Africa, said in a statement on the eve of World Rhino Day on Thursday.

Officials from Vietnam and China, where rhino horns are in demand, will travel to South Africa this month to discuss how to cooperate on poaching investigations, the fund said.

South Africa has arrested more than 165 people in connection with rhino poaching this year, sending some of those convicted to prison for up to 12 years, according to the group. Eleven more poaching suspects are scheduled to go on trial in a South African court next week. They include veterinarians, safari operators and a pilot.

"South African authorities are taking rhino poaching very seriously and are beginning to dismantle the sophisticated criminal gangs that are behind the killings,” Joseph Okori, the fund’s African rhino program manager, said in a statement.

The wildlife group estimates there are 28,038 rhinos left in the world - 20,000 African white rhinos, 4,838 African black rhinos and 3,200 Asian rhinos.