South Africa's security forces have deployed outside hospitals as unions defy a court order to keep essential services open during their strike.
Police have fired rubber bullets at striking health workers, injuring several protesters in Durban.
The army has sent medical teams to 37 hospitals around the country to keep emergency health services open.
Some one million civil servants began their strike on Wednesday, in a dispute over pay.
The government on Saturday obtained an injunction against the strike, which the unions immediately condemned.
The injunction forbids strikers from blockading state buildings and instructs those providing essential services to return to work.
The BBC's Jonah Fisher in Johannesburg says early indications are that the order has had at best a limited impact.
Those shot outside Durban's Addington Hospital were reportedly blockading the staff entrance.
Nurse Buhle Ntsele, who was bleeding from the thigh after being shot, said their protest had been peaceful.
"People who are working have betrayed us. We need to deal with them," the South African Press Agency (Sapa) reports.
Sapa says that some nurses were on duty at the hospital's casualty unit, while there was a heavy police presence outside.
The situation is reportedly similar in hospitals in Johannesburg, with a police and soldiers monitoring protesters at the gates and army medics working inside.
Mugwena Maluleke, a spokesman for the Congress of South African Trade Unions (Cosatu), told the BBC over the weekend that union members would not be advised to return to work.
"We have to highlight our plight. We have told our members, there must be no obstruction of entrances and no intimidation," he told Sapa.
The health ministry has asked for volunteers to help clean hospitals and cook food for patients.
As the strike enters its sixth day, there are signs that the dispute may escalate.
At least one extra teachers' union is expected to join the strike from Monday, while local government workers say they will join the action out of solidarity on Thursday.
The government has offered a 7% pay rise. Unions affiliated to Cosatu are demanding an increase of 8.6%.
The government says it cannot afford to deliver wage increases that amount to twice the rate of inflation.
On Friday, Health Minister Aaron Motsoaledi said hospital workers who interrupted vital medical care and forced colleagues to join the strike are carrying out actions tantamount to murder.
President Jacob Zuma has defended the unions' right to strike but also urged for them to end violence and intimidation.