Striking workers at South Africa's crippled Lonmin mine on Friday rejected a wage offer from the platinum giant intended to end a stayaway that has spread across the mining industry.

Workers dismissed Lonmin's offer as "an insult" after it was presented to them at the company's Marikana plant in the Rustenburg platinum belt, where the world's top producer Anglo American Platinum has also been affected.

"The workers rejected the offer," representative Molisi Phele told AFP of the 986 rand ($120, 92 euros) pay increase put forward by the company.

"Lonmin did not respond to the workers' demand. What they (the workers) say is that their offer is an insult."

The proposal, made in mediated talks late Thursday, was the first to be made by the world's number three platinum producer since it was forced to shut down its Marikana operations more than a month ago.

The unrest has snowballed into workers downing tools at other mines since Lonmin's strike exploded into bloodshed which claimed 45 lives, including 34 miners gunned down by police in violence that sent shockwaves through the world.

Worker delegations are set later Friday to report back their decision to stand firm on demands for a pay hike to 12,500 rands.

"We are going back to tell them (that) the workers say 'Thank you for giving us nothing'," said Phele, who added that workers were calm and collected.

"They just said 'No go' and tell those guys to put 12.5 on the table. If they are unable to do that, thank you, let Lonmin take their bags and go back to London."

The striking miners claim they earn 4,000 rand a month, while the company says workers already earn around 10,000 rand when bonuses and other compensation are included.

Lonmin has warned that an indefinite strike will threaten 40,000 jobs, while Anglo American Platinum (Amplats) sounded the alarm on Friday that South Africa faced the risk of significant job losses due to the growing unrest.

"We as a country, as an industry, should be focusing on getting solutions going forward because the industry is actually at risk especially in the operations in the Rustenburg area," Bongani Nqwababa, Amplats finance director told SAFM public radio.

"The focus should be on job conservation because the risk of significant job losses is very, very high," he added.

Amplats on Wednesday became the second mining giant to be hit by strikes in the platinum belt where it employs 24,000 people, shutting down five mines over safety fears after intimidation threats against miners going to work.

"It's an industry-wide issue and there's contagion," said Nqwababa.

Thousands of miners rallied at the Amplats' complex Thursday with threats to extend their strike before a memorandum of demands was presented to management.

The labour strife has also spread to the gold sector where 15,000 Gold Fields miners have been striking since Sunday.

"I think that the real difficult situation is that the whole thing is being influenced by other mines that have come to bandwagon," said Bishop Jo Seoka who helped broker the mediation talks.

"I think they (Lonmin) are very desperate. I think they want to resolve the matter because it impacts on the platinum industry as a whole, not just them, they realise that and therefore in order to manage the situation they have to provide an answer."

South Africa's President Jacob Zuma warned his government would soon act to rein in the unrest, telling parliament that it was not acceptable but not giving any details as to what actions will be taken.

The backbone of South Africa's economy, the mining industry directly hires around 500,000 people and contributes up to nearly one fifth of GDP when related activities are included.