Union members have warned staff at the Benoni magistrate's and regional courts to stay away from work.
Nomsa Maphanga, Benoni's senior public prosecutor, said union officials arrived at the court building on Wednesday and requested a meeting with her.
"They insisted we were not to report for duty today, otherwise we'd be taken to task," Maphanga said.
"We've decided to postpone cases where possible and to inform the police of postponement dates, which they will take care of at the prisons.
"No prisoners will be released whatsoever on account of this situation," she stated in response to an anonymous caller to The Star who claimed some prisoners were being released unconditionally.
Maphanga said she was insisting that her staff go home, as she didn't want anyone's life to be at risk. "We are rescheduling cases and will inform the parties accordingly."
By Anna Louw The Star