The world's third-largest platinum producer Lonmin on Monday announced it had fired 235 workers who have been on strike for four months -- one of the longest in South Africa's history. Company spokesman Happy Nkhoma said those fired were essential services workers who were not allowed to down tools under an agreement with the Association of Mineworkers and Construction Union (AMCU). "These are employees who have been absent since January 23, so the recent intimidation does not explain their absence," Nkhoma told the Sapa news agency. He cited a court ruling issued in February ordering essential workers to resume work by May 12. Many workers want to go back to work but are terrified of their striking colleagues after several acts of intimidation including the deaths of three miners last week. Lonmin has not released figures on how many workers have returned to their posts. "We understand that every employee that reported for duty braved high intimidation and threats to do so. We shall release statistics once it is safe to do so," said Nkhoma. Since January, the three largest producers in the world have suffered a crippling strike by some 80,000 workers on South Africa's restive platinum belt, north of Johannesburg. Lonmin, has been the worst affected, with a 43 percent drop in production. Lonmin, Anglo American Platinum and Impala Platinum have lost 18.6 billion rand (1 billion euros, $1.7 billion)in revenues. South Africa accounts for 80 percent of the world's platinum supply and nearly a third of the world's palladium. The crisis has so far had muted effects on platinum prices, which commodity analysts put down to ore stockpiling, production lead times and sourcing from other producers. AMCU is demanding workers' salaries be doubled to 12,500 rand as base pay excluding benefits and has rejected the employers' offer of 12,500 as a total package.