Four people have been arrested after explosives and firearms were found in Bronkhorstspruit, east of Pretoria.
Police spokesperson Johannes Jafta told the SABC that police were tipped off after neighbours heard gunshots at a smallholding.
The items discovered included nine firearms, shotgun ammunition, grenades and dagga.
He said the police were investigating the origin of the firearms and ammunition.
The four people who were arrested were expected to appear in court soon.