A total of 102 rhino have been killed since the beginning of the year, says the department of environmental affairs.
Spokesperson Albi Modise said on Wednesday that the Kruger National Park (KNP) was the hardest hit, with four rhino being killed there this week alone.
A total of 70 KNP rhino have been killed since January 1.
"In the past 48 hours five alleged poachers were arrested in Limpopo and one in the KNP. This means a total of 40 alleged poachers, among them three alleged couriers, have been arrested since the beginning of the year," said Modise.
Police officers recovered ammunition, rifles and a silencer from the suspected poachers.
A total of 11 rhino have been poached in the North West, 10 in KwaZulu-Natal, seven in Limpopo and four in Mpumalanga.
Modise said while the numbers remained high, there was a slight drop in the number of rhino killed per week.
"[It] may be attributed to the implementation of the turnaround strategy aimed at eliminating poaching by the SA National Parks," he said.
Last year, the country recorded that three rhino were being poached per week.
This year, the number had dropped to two.
Over 630 rhino were killed by poachers in 2012. – Sapa