Labour unrest grows in South Africa as police say 1,000 strikers are blocking access to the main shaft at Anglo American Platinum, stopping some operations at the world's largest platinum mine.

Anglo spokeswoman Mpumi Sithole said threats and intimidation from "unidentified individuals" had stopped some miners working overnight.

Police spokesman Brig. Thulani Ngubane said 1,000 miners blocked access to the mine near Rustenburg, northwest of Johannesburg.

Sithole said other miners have been moved away for their "safety and security." She said some operations have stopped.

Neighbouring Lonmin PLC platinum mine has been on strike for a month with workers demanding that others join them. They are demanding a take-home monthly pay of 12,500 rand ($1,560), about double their salary. Forty-five people have died at Lonmin, including 34 shot by police.