South Korea on Tuesday decided to expand its special quarantine procedures to people coming from all countries of the world as concerns about imported cases are rising after COVID-19 was declared a pandemic.

Starting Thursday, all people arriving in South Korea will be subject to the special quarantine measures, according to the Korea Centers for Disease Control and Prevention (KCDC).

All arrivals should have their temperature checked and fill out health documents at airports. They should notify health authorities of their addresses here and phone numbers where they can be reached, and also download a self-check app to report their health conditions.

"The number of arrivals testing positive for the virus or showing symptoms has been increasing recently," Vice Health Minister Kim Ganglip said at a press briefing. "We are now in an important situation to control imported cases from various regions."

According to local health authorities, more than 13,000 people entered the country on Monday.

South Korea's latest measure come only a day after the country decided to impose special quarantine procedures on arrivals from all European countries, in addition to those from China, Japan, Iran, Hong Kong and Macao.

The daily number of new infections in South Korea has been in the double digits for the last three days, showing signs of a slowdown in new cases, while the number of COVID-19 cases in Europe and other regions have soared.

So far, more than 168,000 COVID-19 cases have been confirmed in over 140 countries, with nearly half reported in China, according to the World Health Organization (WHO), which declared the new coronavirus outbreak a pandemic last week.

The KCDC on Tuesday said that six imported cases were identified at airport screening checkpoints in the past four days, an alarming development for the country considering that no cases had been confirmed at airport checkpoints in nearly three weeks.

As of Tuesday, the total number of imported virus cases identified in South Korea was 55, including 27 from European nations and 16 from China. Of the 55 imported cases, 47 were South Korean nationals followed by six Chinese.

However, experts said the number of imported cases could increase further. Of the 1,391 passengers who arrived from European countries Monday, 76 have undergone tests after showing COVID-19 symptoms, according to the KCDC.

"We are now at a point where imported virus cases can cause problems," said Bang Ji-hwan, a doctor at Seoul National University Boramae Hospital in Seoul. "The entire world is dealing with this pandemic, and it's impossible for us alone to have no virus patients."

Some experts said South Korea should consider implementing stricter quarantine measures.

Unlike other countries banning the entry of travelers from virus-hit countries or putting all people visiting such nations under mandatory two-week quarantine, South Korea has only done so for foreigners who traveled to Hubei Province in China, the global epicenter of the disease.

"The government should come up with preemptive and powerful measures on those who have a risk of virus transmission," said Jung Ki-suck, a doctor at Hallym University Sacred Heart Hospital and former head of the KCDC. "It requires those from virus-hit countries to use a self-diagnosis app, but if their symptoms are mild, people may think that they have not contracted the virus and may not report to health authorities."

Doctors said the authorities should also focus on travel controls for South Koreans planning overseas trips.

"Entry bans will not be able to stop all virus infections," said Uhm Joong-shik, a doctor at Gachon University Gil Medical Center in Incheon, just west of Seoul. "The government should also control people who are to visit virus-hit countries, because they could return here infected with COVID-19." (Yonhap)