The Emfuleni municipality will not re-employ 28 temporary workers who demonstrated at the Boipatong, Vanderbijlpark, waste management offices, even if permanent posts became available.
Deputy municipal manager Sam Shabalala said the contracts of the workers, who demonstrated on Wednesday morning, would not be renewed when they expired today.
Charges against the municipal workers were withdrawn yesterday in the Vanderbijlpark magistrates' court.
They were arrested after they went on the rampage by burning tyres and locking the gates of the municipal offices.
The demonstrators denied the police entry and then threw stones and bricks at the police, who retaliated by firing stun grenades and rubber bullets. The standoff lasted for about four hours, after which the workers surrendered and handed themselves over to the police.
The protesters said they were angry because the municipality refused to employ them permanently.
Shabalala said: "We were fully aware of the demonstrators' allegations and had informed them much earlier that their contracts were not going to be renewed.
"They have burnt their bridges. How can we reconsider them in future if they are violent?"