Poachers have slaughtered 32 South African rhinos in the first three weeks of 2013, marking a disturbing start to the year for a country battling crisis level killings of the beast, government said Wednesday.

A record 668 rhinos were killed last year, most of them in the vast wildlife reserve and the country's top safari destination, Kruger National Park.

The killings continue despite the deployment of soldiers and a surveillance aircraft in the two-million-hectare (five-million-acre) Kruger Park.

Rhinos are victims of surging demand for their horns in some Asian countries where it is thought to have medicinal properties, although the claim is widely discredited.

South Africa and Vietnam last year signed a deal to tackle the trade and several Asian nationals have been arrested for involvement in poaching.

The number of rhinos poached in the country has shot to dizzying levels over the last five years, from 13 in 2007 to 448 in 2011, and 668 last year.