The country's mining sector has recorded 411 confirmed cases and one death due to the global pandemic, according to the Minerals Council South Africa, from more than 218,000 employees screened and 6,528 tested.
Sibanye-Stillwater (JSE: SSW) confirmed last week 51 employees had tested positive for COVID-19 at its Thembelani mine at its Rustenburg platinum group metals operation, taking its total to 65 at its South Africa assets.
The company said there was a high number of asymptomatic cases, a similar situation AngloGold Ashanti outlined last week when it reported 196 cases at its Mponeng gold mine.
Mantashe described the number of people showing no signs of COVID-19 but testing positive as a new complication.
"This tells us that we need to intensify our screening and testing programme," he said on Friday.
"We urge all mining operations to pull their resources together and share testing and quarantine facilities."
He said unannounced visits to mines would continue to monitor compliance with the country's mandatory COVID-19 guidelines.
The minerals council warned last week of an 8-10% impact on mining production this year due to COVID-19 and said South Africa was facing a deep economic recession due to overdue structural changes, compounded by the pandemic.