President Cyril Ramaphosa says he is concerned about the ongoing wage strike by public workers that is affecting essential services in the country.

The strike by the National Education, Health and Allied Workers' Union (Nehawu) started on Monday, as the workers demanded a 10% pay hike after rejecting the government's 3% increase.

At least four people have died as the workers reportedly prevented patients from entering numerous hospitals and clinics in the country, Health Minister Joe Phaahla said.

The president said on Thursday that while workers have a right to strike, acts of violence would not be tolerated.

“We are all concerned about the violent nature of the strike that is under way. Workers in our country have the right to freedom of association and to strike. But that right is not absolute," President Ramaphosa said.

He said that the "no work, no pay" principle should apply to essential services workers who go on strike.