Members of Operation Dudula and EFF have clashed outside Kalafong Hospital in Pretoria. This is ahead of the visit by Health minister Dr Joe Phaahla to the hospital today.
Police had to use stun grenades to disperse the warring factions.
Dudula members had arrived at the hospital in the morning to protest against undocumented foreign nationals allegedly accessing healthcare at the institution.
The provincial health department said it obtained a court interdict on August 26 from the Pretoria High Court to stop Dudula members threatening or denying patients and employees access to the hospital.
A copy of the order was posted on the notice boards outside the hospital on Thursday.