Two cases of assault, allegedly by striking metal and engineering workers, were being investigated by Germiston police yesterday.
Captain Steady Nawa said two men were beaten with sticks and knobkerries in separate incidents in Germiston on Wednesday.
At 7.55am a man walking along Sigma Street was assaulted after telling a group of protesters that he was going to work.
At 9.30am another worker was beaten when he went to fetch something from his car outside company premises in Smit Street.
No arrests have been made, but Nawa said police would "take action soon". He appealed to the strikers to refrain from violence.
"We will take drastic action against those who commit crime in the name of industrial action," he said. - Sapa