Twenty-eight female guards were unfairly dismissed by a security company because the client‚ Metrora.
Mittal Steel South Africa said yesterday that it knew nothing of planned protests by its workers' union over high steel prices.
"Mittal has no knowledge of any industrial action planned by Numsa," said Tami Didiza, Mittal's spokesman.
"This matter has certainly never been raised with us by the union at any of our meetings."
The National Union of Metalworkers (Numsa) on Tuesday said it would "mobilise work stoppages and demonstrations in protest against steel price increases".
No definite date had been announced for the start of the campaign, which was still being planned, said Numsa spokesman Mziwakhe Hlangani. - Sapa