platinum said on Friday that production had been hit by a strike amid plans to cut 3,330 jobs.
The company said around 20 percent of workers had turned up at the firm's Rustenburg and Pilanesburg operations, in South Africa's platinum belt.
"Production will be impacted by the strike action although sales will not be impacted at this point," the company said in a statement.
"Anglo American Platinum is monitoring the situation and working closely with local authorities to ensure that there is peace and stability during the strike."
The striking workers are affiliated with the hard-line AMCU union, which is involved in a fierce battle for supremacy.
They had called the strike after the company on September 2 handed 3,300 employees dismissal notices as part of a restructuring and announced earlier it would offer a further 1,600 workers voluntary severance packages.
The industrial action occurs amid on-going unrest in the mining sector, which accounts for a fifth of Africa's largest economy.
Violent strikes spread across the industry in August 2012 after a deadly police crackdown at Lonmin's platinum mine in Marikana, where officers shot dead 34 people in one day.
Amplats CEO Chris Griffith warned further unrest could spell deeper job cuts.
"Strikes and work stoppages will result in further losses that will hamper plans for future sustainability and further threaten the future of our 45,000 employees."
The police reported no incidents of violence.