At least 45 people have now died in the violence that has been engulfing parts of South Africa since the jailing of former President Jacob Zuma last week.
This includes 10 people killed in a stampede during looting on Monday night at a shopping centre in Soweto, the country’s biggest township.
Almost 800 people have been arrested in the unrest that began last Thursday and turned violent over the weekend.
The military has now been deployed to help the overstretched police.
President Cyril Ramaphosa has called it some of the worst violence witnessed in South Africa since the 1990s.
Police Minister Bheki Cele told journalists on Tuesday that, if the looting continued, there was a risk areas could run out of basic food supplies.
However, Defence Minister Nosiviwe Mapisa-Nqakula said there was not yet a need to declare a state of emergency over the violence.