South Africa's health minister has told striking public sector workers that those who interrupted vital medical care were guilty of murder.
Aaron Motsoaledi, a doctor by training, said he was shocked by the intimidation tactics used by some of the protesters.
More than a million civil servants began an indefinite strike on Wednesday, calling for higher wages.
Soldiers have been deployed to some hospitals after unruly demonstrations and army medics are helping out.
There has been little sign of progress in pay talks with the unions affiliated with Cosatu, South Africa's main union federation, holding out for an 8.6% pay rise.
But the government has repeated its appeal to strikers that it cannot afford to deliver wage increases that amount to twice the rate of inflation.
It says it can barely afford the 7% offer it has put on the table for the police, teachers, doctors and nurses.
The BBC's Karen Allen in Johannesburg says on the third day of industrial action many hospitals tightened access and wards were being run with the assistance of volunteers who are helping to care for patients, cook and change bed linen.
Appeals have been made for more volunteers to help out at hospitals and at schools, she says.
Dr Motsoaledi has himself been working at the Chris Hani Baragwanath Hospital in Soweto, where police fired rubber bullets and water canon at striking workers on Thursday who were trying to stop people entering the hospital.
"I'm not surprised but shocked, extremely shocked at the willingness to murder because you can't have that kind of country," the South African Press Association quotes him as saying.
"We have demonstrated our humanity during the World Cup. Why now are people losing their humanity and prepared to murder?" Dr Motsoaledi said.
President Jacob Zuma has defended the unions' right to strike but also urged for them to end violence and intimidation.
Our reporter says on Friday many frail elderly patients were discharged early and told to come back after the weekend when they may be readmitted.