South Korea has raised its coronavirus alert to the “highest level” as confirmed case numbers keep rising.
President Moon Jae-in said the country faced “a grave turning point”, and the next few days would be crucial in the battle to contain the outbreak.
Six people have died from the virus in South Korea and more than 600 have been infected.
Meanwhile, Italy and Iran have announced steps to try to contain worrying outbreaks of the virus.
In Italy, strict quarantine restrictions are in force in two northern “hotspot” regions close to Milan and Venice.
Around 50,000 people cannot enter or leave several towns in Veneto and Lombardy for the next two weeks without special permission. Even outside the zone, many businesses and schools have suspended activities, and sporting events have been cancelled including several top-flight football matches.
Amid the growing restrictions, the last two days of the Venice Carnival, on Monday and Tuesday, were cancelled.
Italy has seen two deaths and the number of confirmed cases has risen to more than 100 – 89 of them in Lombardy.
“The contagiousness of this virus is very strong and pretty virulent,” said Lombardy’s health chief, Giulio Gallera.
Iran’s outbreak of coronavirus has significantly worsened, with the death toll rising to eight on Sunday. The government has acknowledged 43 confirmed cases although officials have warned the virus may have spread to “all cities”.
Schools, universities and cultural centres across 14 Iranian provinces have been closed from Sunday.
The new strain of coronavirus, which originated last year in Hubei province in China, causes a respiratory disease called Covid-19. China has seen more than 76,000 infections and 2,442 deaths.
On Sunday, China’s President Xi Jinping described the outbreak as the “largest public health emergency” in the country’s recent history.
He acknowledged “shortcomings” in China’s response and said lessons must be learned.