South Korea is instituting amplified checks on arrivals at its air and sea ports to monitor infections coming in from abroad.

The Korea Centers for Disease Control and Prevention said Thursday that of 64,497 arrivals at the Incheon and Gimhae international airports in the past week, 17 had tested positive for the virus. So far, 79 returnees and travelers were later found to be infected after their viral status went undetected upon arrival.

For tightened virus checks on returnees as well as travelers, health authorities have mobilized 474 additional officers for a total of 879 in charge of screening duties at five ports of entry nationwide.

A 51-room facility for housing symptomatic arrivers will be set up Yoengjongdo, an island off the west coast of Incheon, to meet growing demand. Over 6,000 people entered Korea on Thursday alone.

Between Feb. 4 and Wednesday, about 844 have been accommodated at the quarantine facility at Incheon Airport.

Kwon Jun-wook, the centers’ vice director, advised those returning after overseas trips to limit outings for 14 days and alert authorities in the event of virus symptoms via its 1339 hotline or a mobile application launched last month for self-diagnosing symptoms.

As of Thursday, Korea’s virus tally stands at 8,565, up 152 from the same time a day prior. The country’s worst-hit city of Daegu saw the largest daily increase of 97, followed by Gyeonggi Province with 18 new cases, North Gyeongsang Province with 12 and Seoul with 12.

Infections broke out at hospitals and care facilities across the country.

Four more cases were detected at a hospital in Bundang, Gyeonggi Province, which is now linked to 35 virus patients including the hospital’s director, surnamed Lee. Vice Health Minister Kim Gang-lip and seven other ministry officials who came into contact with Lee in a conference on March 13 have gone into self-quarantine for two weeks.

Eight were confirmed to have the virus at a hospital in northern Daegu, while 74 were found infected at a nursing home in a southern district in the city. Thirteen more infections were discovered at four nursing homes in other parts of the country.

Religious events continue to be a contributing factor to the rise in infections.

A Protestant church in Daegu has been associated with at least 55 cases since the first there emerged March 9.

In a press briefing held the same day, senior Health Ministry official Yoon Tae-ho said as schools were set to open in two weeks, measures were being drafted to protect children from possible exposure.

He said venues frequented by children and adolescents such as gaming cafes and karaoke rooms have been advised to take precautions to mitigate the spread.

Health officials once again warned against all social gatherings and interactions and urged strict observation of social distancing.

Community transmissions involving group activities account for over 80 percent of all cases here, according to the latest data.

“Social distancing is the only way to fight the disease without cure or vaccine, and everyone has to play his or her part by avoiding nonessential contact,” Yoon said.

“The worst imaginable is coming true with the COVID-19 crisis,” said Kwon. “The disease control headquarters is determined to win this fight. The whole world is in the fight against the virus, and racing to develop vaccines and treatments. I have no doubt we will win this battle.”

“But until then, we all have to partake in practicing social distancing and good hygiene. These are the norms demanded by the reality we are facing,” he said.

By Kim Arin (arin@heraldcorp.com)