The South Korean government on Saturday urged citizens to stay at home as the country struggled with rising cases of novel coronavirus, or COVID-19, Reuters reported. The total number of infections in South Korea jumped to 3,150 on Saturday – the addition of 813 cases being the biggest single-day increase so far.

Four more people died of the infection in South Korea, taking the toll to 17, the Korea Centers for Disease Control and Prevention said. A 73-year-old woman who had been discharged from hospital after recovery last week has tested positive again, authorities said. This was the first case of re-infection in the country.

More than 90% of the new cases were in and around the city of Daegu, which has been the epicentre of the outbreak in South Korea. The city’s streets have been deserted for days, apart from long queues to buy masks, according to AFP.

“We have asked you to refrain from taking part in public events, including a religious gathering or protest, this weekend,” Vice Health Minister Kim Kang-lip said. He added it was a “critical moment” in reining in the spread of the virus.

China, where the outbreak began, reported 427 new confirmed cases and 47 deaths on Friday. The total number of confirmed cases on the mainland reached 79,251, with 2,835 deaths, the National Health Commission said.

Michael Ryan, the executive director of World Health Organization’s Health Emergencies Programme, said on Friday that it was unhelpful to declare a pandemic yet when countries were still trying to contain the disease. “A pandemic is a unique situation, in which all citizens on the planet will likely be exposed to a virus within a defined period of time,” Xinhua news agency quoted Ryan as saying.

The WHO also revised the risk assessment of the coronavirus from high to “very high” at global level.

In Iran, the number of cases reached 593, and 43 people have died so far. The government urged people to stay away from mass gatherings and limit their travel, AP reported.

Barring China, South Korea has the highest number of cases and Iran the most deaths.