Officials said on Saturday that 229 new cases had been confirmed since Friday, raising the total to 433.
In a televised address, Prime Minister Chung Sye-kyun described the situation as “grave”.
Two patients in South Korea have died so far and there are fears the number will rise.
South Korea has now reported the largest number of confirmed infections after China – 76,288 cases including 2,345 deaths – and the outbreak on the Diamond Princess cruise ship off the coast of Japan which has seen more than 600 cases.
He said the greatest concern now was countries with weaker health systems, particularly in Africa.
In other developments:
- Thirty-two British and other European cruise ship passengers are in quarantine in north-west England after arriving back from Japan
- Israel refused to allow some 200 non-Israelis to disembark from a plane which had arrived from South Korea, sending them back to Seoul; the 12 Israelis on board were quarantined. Israel suspended all flights from Japan and South Korea on Saturday after confirming its first case of the virus on Friday
- Italy reported its second death from the virus – a woman living in the northern region of Lombardy – a day after a 78-year-old man became the first person in Italy to die from the new coronavirus. The country now has nearly 60 cases
- Iran reported its fifth death from the disease, and ordered the closure of schools, universities and cultural centres in 14 provinces. The outbreak is centred on the holy city of Qom but officials warned that the virus may already have spread to “all cities in Iran”
The new virus, which originated last year in Hubei province in China, causes a respiratory disease called Covid-19.
What happened in South Korea?
Medical officials first announced 142 new cases on Saturday and then hours later increased the number by 87.
In a statement, the Korea Centers for Disease Control and Prevention (KCDC) said that of the 229 new cases, 95 were related to Daenam Hospital in Cheongdo, which treats the elderly and people with mental health issues. There are now 114 confirmed cases at the hospital – nine staff and 102 patients – it added.
Vice Health Minister Kim Gang-lip said the outbreak had entered “a serious new phase”.
He said most of those diagnosed at the hospital had been inpatients for mental illnesses. Some cases showed “no confirmed epidemiological connections”, meaning it was not clear how they had contracted the virus, he added.
In his national address, Prime Minister Chung asked South Koreans to avoid large gatherings, including religious events.
What has the WHO said?
In a briefing to the African Union on Saturday, Dr Tedros said the WHO was working with African governments to train thousands of health workers and to provide equipment to identify and treat infected people.
“Our biggest concern continues to be the potential for Covid-19 to spread in countries with weaker health systems,” he said. “We are working hard to prepare countries in Africa for the potential arrival of the virus.”
“This is a great example of how investing in health systems can pay dividends for health security,” he said.
What’s happening elsewhere?
Australian officials said on Friday that six people had reported feeling unwell on arrival in Darwin and were immediately tested. Two of those people tested positive despite having received negative tests before leaving Japan.