The police arrested 20 people suspected of illegal mining in Matholesville, Roodepoort, on Tuesday.
Police spokesperson Captain Kay Makhubele said this brought to 30 the number of arrests since an operation targeting this kind of mining began in the area a week ago.
Equipment believed to be used during the commission of illegal mining was seized. Shacks and other illegal structures were also demolished during the operation at the old "Durban Deep" mine.
Illegal electricity connections and water pipes were disconnected.
"Members of the public have been cautioned to guard against using their economic status to commit crime because the police will not hesitate to arrest any person involved in unlawful activities," said Makhubele.
Those arrested will appear in the Roodepoort Magistrate's Court soon.
A similar raid was conducted in the area at the beginning of July.