South Africa says it has arrested 89 suspected rhino poachers this year as part of an efforts to beef up its campaign to curb poaching.

There were 165 arrests in 2010 and 232 suspected poachers were arrested last year, including 26 who died in clashes with enforcement authorities, officials said.

Even with the stepped-up campaign there has been a surge in rhino poaching.

A total of 135 endangered rhino have been killed by poachers this year, the country's environment department said, about a third of the number killed in 2011.

The World Wide Fund for Nature has linked the recent upsurge in rhino poaching to increased demand for rhino horn.

The demand is mostly from Asia, particularly Vietnam, China's official Xinhua news agency reported.

"Rhino horn has gained popularity among wealthy Vietnamese elites and business people to give as a gift, when currying political favor, or taking as an antidote to overindulgence," said Tom Milliken of wildlife trade monitoring group TRAFFIC. "But killing endangered rhinos to mitigate a hangover is a criminal way to see in the New Year."