Johannesburg — Mine security used water cannons on strikers at Anglo American Platinum's (Amplats) Khuseleka mine in Rustenburg, the Association of Mineworkers and Construction Union (Amcu) said on Friday.
"The situation is out of control, it is tense," said co-ordinator Evans Ramokga.
"Mine police [security] without any provocation sprayed workers with water. The workers had gathered to picket outside the mine's operation."
He said the workers retaliated by pelting the security staff with stones.
"If there was anything wrong, they should have informed marshals or contacted me."
Amcu members at Amplats, Impala Platinum and Lonmin went on strike on Thursday demanding entry-level monthly salaries of R12,500.
On Thursday, he said the union had roped in more marshals to ensure that the strike was peaceful.
North West police could not immediately confirm the incident.