A "special care zone" has been set up in the South Korean city of Gyeongsan after it saw a spike in coronavirus cases.
Similar zones have been declared around neighbouring Daegu city and Cheongdo County, with face masks being provided and residents warned against travelling.
Health officials said dozens of newly commissioned military nurses are due to begin work in Daegu on Thursday to help the patients.
Meanwhile, the US military confirmed two new cases among relatives of its troops in the country.
It comes as Australia joined almost 100 nations to impose travel restrictions on South Koreans.
Nine injured in attack in Taipei, media reports
Putin offers no compromise on Ukraine, says EU 'robbery' failed
Bangladesh rocked by unrest after death of student leader
Suspected gunman in Brown University shooting found dead
Ukraine's Zelenskyy meets Poland's Trump-backed president at key moment in war
No evidence alleged Bondi gunmen received military training in Philippines
At least 12 killed in Nigeria mining site attack
Russian attack on Ukraine's central Cherkasy injures six, causes blackouts
