A contract worker has died at Harmony Gold's Target mine in the Free State, the company said on Friday in a statement.

The accident occurred on Tuesday and the cause of death was electrocution.

Investigations of the equipment used were also underway to establish the reasons for the electrocution.

"Production was not hindered by the accident," the company said.

However, the National Union of Mineworkers had declared a day of mourning that commenced on Thursday night and would continue for the duration of Friday, Harmony added.

The company said it continued to address safety through its behaviour-based initiatives that had been rolled out to all of its operations.

"The continuous communication on safety in the working place as well as off the job is receiving priority attention from all stakeholders involved," the statement said.