Anglo American Platinum Ltd., or Amplats, dismissed about 50% of its underground workforce at the Mototolo platinum mine in South Africa following an unprotected strike that began May 12.

The company laid off 643 people, according to Reuters.

The General Industrial Workers Union of South Africa served a strike notice to the company May 9 regarding changes to the employee medical program after Anglo purchased the mine from Glencore PLC in November 2018. Amplats had offered a medical program with similar benefits.

On May 10, the company was granted an interim court interdict against any strike action at the mine, but the union defied the court order.

Amplats said May 20 that its appeals to end the action were ignored by the striking employees.

The dismissed employees have until May 21 to appeal the company's decision.

Amplats added that the impact on production is minimal so far, and it is exploring options to ensure that Mototolo restarts full production as soon as possible.

Amplats is majority owned by Anglo American PLC.