Police fired water cannons and rubber bullets to block scores of striking workers from a Johannesburg hospital, on the second day of a stay-away by public sector staff.
About 1.3 million workers on Wednesday began an open-ended strike to demand higher wages, but so far protests have been limited to small groups picketing outside schools and hospitals.
But about 150 health workers protesting outside the 3.000-bed Chris Hani Baragwanath Hospital, which serves the sprawling township of Soweto, tried to enter the building.
Police used water cannons and rubber bullets to push back protesters, a scene local media said was repeated at a second hospital across the city.
Striking teachers say they plan to blockade a major highway later in the day. Police were already lining nearby roads ahead of the protest.
Health workers, like police and immigration agents, are considered essential services and not allowed to strike. But support staff at hospitals have joined the stayaway.
‘Hit in their legs’
"Some people were hit in their legs, some in their bodies. Some of the people were hurt" by the rubber bullets, said Hamilton Maswanganyi, a hospital gardener. He said strikers were upset that their colleagues were still working inside.
Cabinet spokesman Themba Maseko denounced the few such incidents of violence, and said military doctors were on standby in case they are needed at public hospitals.
"Cabinet condemns unreservedly the violence, intimidation and the acts bordering on thuggery and criminality, that has characterised the strike in parts of the country," he says.
"The defence force will be on stand-by to provide assistance in emergency and life-threatening situations such as providing urgently needed medical care."
Rowdy strikes are annual events in South Africa, where contracts come up for renewal mid-year. This year public workers postponed their strike threat until after the football World Cup, a gesture that did little to close the gap with government over wages.