Poachers slaughtered a record 668 rhinos in South Africa last year as demand for their horns continued to surge on the black market in Asia, the government said Thursday.
Over 60 percent of the slaughtered pachyderms were from the vast Kruger National Park, South Africa's largest wildlife reserve and the country's top safari destination.
Five more animals have been killed since the start of this year, according to the environmental affairs ministry.
Poaching-related arrests climbed from 165 in 2010 to 267 in 2012.
South Africa is home to about three-quarters of Africa's 20,000 or so white rhinos and 4,800 critically endangered black rhinos.
Authorities have launched inter-linking campaigns to slow the killings.
Soldiers and surveillance aircraft were deployed in the Kruger Park, while stricter criteria for rhino hunting permits saw applications tumble to 90 in 2012, down from 222 a year before.
Rhinos are victims of a booming demand for their horns, which some people in Asia think have medicinal properties. The medical claim is widely discredited.
South Africa and Vietnam last year signed a deal to tackle the trade.
The World Wildlife Foundation hailed the agreement but highlighted "an urgent need to work closely with countries which are transit routes for illicit rhino horn, specifically Mozambique," WWF South Africa rhino coordinator Jo Shaw said in a statement Thursday.
"Both Mozambique and Vietnam have been given failing grades by WWF's Wildlife Crime Scorecard for failing to enforce laws meant to protect rhinos," the body said.
This week Thai and Vietnamese airport authorities seized over 27 kilogrammes of rhino horn in separate incidents.
The number of rhinos poached in South Africa has risen sharply from 13 in 2007 to 448 in 2011.
Explore further: Nearly 200 rhinos killed this year in South Africa: WWF