Rustenburg - Security blocked access to the Lonmin platinum mine in Rustenburg in the North West on Tuesday morning.
Cars transporting personnel were seen entering the mine every few minutes.
They were the only people who were allowed access, after last week's protest action by mineworkers.
The protest action culminated in clashes with the police on Thursday, which saw 34 miners shot dead, more than 70 injured and 259 arrested.
Lonmin on Monday extended its ultimatum for workers to return to their jobs on Tuesday morning or face dismissal.
On Tuesday morning, Lonmin mine said its objective was not just to dismiss people, but to find a reasonable solution to the situation.
Lonmin executive vice-president for mining Mark Munroe told Talk Radio 702: "A deadline or ultimatum is not helping anyone.
"We strongly encourage people to come to work as soon as possible. There is a lot of action you can take before you dismiss someone."
Minister in the Presidency Collins Chabane called on Lonmin to suspend the Tuesday morning deadline.
"We hope they will understand the gravity of the situation," Chabane told SAfm.
After discussions with mine management "we thought they (the mine) understood that", he said.
Police were patrolling the area and assisting mine security at various access points.
From the main road in Marikana, 2km away from the mine shaft, a bus carrying workers was seen entering the premises.
Various police vehicles were also seen patrolling the Wonderkop area where miners and community members gathered on Monday.
The protests were believed to be linked to rivalry between the National Union of Mineworkers and the Association of Mineworkers and Construction Union over recognition agreements at the mine.
Workers also wanted higher pay.