At least 220 endangered rhinos have been lost to the poachers for their horns in South Africa since the beginning of this year, a government department said on Tuesday.

Group of white rhino drinking from a waterhole, Kruger National Park, South Africa.?[File photo]

Among the slaughtered rhinos, 207 were killed in the famous Kruger National Park in the northeastern province of Limpopo, and the reserves in the central northern province of the North West and the southeastern province of KwaZulu-Natal, said the Department of Environmental Affairs.

In 2011, a total of 448 rhinos were killed in South Africa, compared to 333 in 2010.

Conservationists have warned the rhino in South Africa is facing their worst poaching crisis in decades.

If the killing trend continues at this rate, it is expected that at least 500 rhinos will be illegally slaughtered by the end of 2012. "The department, our provinces and public entities view this illegal killing of our national treasure in a very serious light, and will continue to prioritize our fight against this crime with other law enforcement agencies," said the department spokesperson Albi Modise.

A total of 146 arrests have been made in an effort to curb the illegal poaching of the rhino this year, according to the department.

South Africa is home to the largest endangered rhino population in the world of about 20, 000, occupying nearly 80 percent of the global total population of rhino.