A strike at the world's third-largest platinum mine enters its fourth week with empty buses searching in vain for workers though wage negotiations may start.

Strikers or miners fearful of death threats did not show up for work Monday at the London-registered Lonmin PLC mine though many say they're feeling the pinch of the no-work, no-pay strike.

Union rivalry continues to play a role. A breakaway union says it will show up for the wage talks only if it's a full participant.

Lonmin had hoped people would show up for work under a peace agreement signed with three major unions, but not the breakaway one. Striking workers say they are interested only in demands to double their salaries. They want a take-home pay of R12,500 ($1,560).