SEOUL (Reuters) - Authorities in South Korea pleaded with the public on Friday to stay indoors and avoid large gatherings as new coronavirus cases hovered close to 100 a day, while tighter border checks on people arriving from the United States took effect.

A woman wearing a protective face mask to prevent contracting the coronavirus disease (COVID-19) walks stairs in Seoul, South Korea March 25, 2020. REUTERS/Kim Hong-ji

South Korea reported 91 new coronavirus cases on Friday, taking its tally to 9,332, the Korea Centers for Disease Control and Prevention (KCDC) said. The death toll rose by 13 to reach a total of 144.

It has reported similar daily numbers for the past two weeks, down from a high of more than 900 in late February.

But a recent surge in imported cases has prompted authorities to toughen entry rules for travelers from Europe and the United States.

The government has sought to convince a restless public that several more weeks of social distancing and self-isolation may be needed to give health authorities time to tamp down the smaller but still steady stream of new cases.

“People may no longer want to maintain social distancing as the spring has come and flowers are blossoming,” Prime Minister Chung Sye-kyun told a news conference.

“But isn’t it better to work harder to end the current pain then to suffer it for a long time?”

People arriving from the United States have to spend two weeks in quarantine and those showing symptoms like fever will be tested. Tighter rules, including a mandatory test and quarantine took effect on Thursday for visitors from Europe on long-term visas.

South Korea has installed “walk-through” testing stations at Incheon airport to meet the need for checks.

The tent-like facilities, set up just outside the airport, are capable of running more than 10 tests an hour, whereas regular hospitals conduct up to three and drive-through stations handle six to eight, the health ministry said.

The government said on Friday it would require all inbound flights to check passengers’ temperatures starting from Monday and anyone with a temperature over 37.5 Celsius (99.5 Fahrenheit) would be denied entry.

The number of infected travelers has increased by more than fivefold to 309 over the past two weeks, 90% of them returning South Koreans, according to the KCDC.

U.S. MILITARY ON ALERT

The U.S. military this week took steps to try to restrict the movements of roughly 28,500 American troops in South Korea.

On Friday, United States Forces Korea (USFK) reported that an American contractor had tested positive, the third case to be confirmed this week among Americans working at the sprawling Camp Humphreys, where the U.S. military is headquartered.

Late on Thursday, an American soldier stationed at the camp south of Seoul tested positive, as did another American contractor also working there this week.

In all, 12 people - including two soldiers - linked to USFK have tested positive.

USFK declared a public health emergency, which gives commanders more authority to ensure “total force compliance” with regulations aimed at stopping the spread of infections by restricting the movements not only of troops, but also their families, as well as civilians who work on the bases.

“We cannot allow the actions of a few, who knowingly and selfishly take matters into their own hands, place the rest of population at an unacceptable level of risk,” USFK said in a letter this week.

As recently as Wednesday a Facebook page affiliated with Camp Humphreys had advertised entertainment events for Thursday and Friday. It was unclear if those events were canceled, but new statements on the camp’s social media sites said as of Friday all movement on the base was restricted to “only bare necessities, which means food and life-health-safety”.