MARIKANA, South Africa (AP) -- Strikes have cost South Africa close to 4.5 billion rand (nearly $563 million) in lost gold and platinum production, President Jacob Zuma announced Monday as the mine where labor unrest began said it is halting work on shaft construction that will cost 1,200 jobs.

The strikes that have stopped work at seven gold and platinum mines also spread to the chrome sector, according to the South African Press Association. And police blocked politician Julius Malema, a diehard Zuma opponent, from addressing some 3,000 strikers gathered at a stadium at the Lonmin mine at Marikana, northwest of Johannesburg.

"Arrest him!" one officer ordered, giving Malema 20 minutes to leave or face arrest. This caused Malema to take off with his entourage.

"I'm leaving. We're getting out of here. Why are you chasing me? Are you going to shoot me?" Malema taunted, a reference to the police shooting of striking Lonmin miners, killing 34, on Aug. 16 in the worst state violence since apartheid ended in 1994.

David Fuller's view This difficult dispute has raised the floor beneath precious metals by reminding investors that supplies are scarce, not least relative to fiat money creation.