Concerns are mounting about a possible hospital bed shortage as daily new coronavirus cases in the country spiked to a nearly six-month high, health experts said Thursday.

South Korea reported 441 new COVID-19 cases, raising the total caseload to 18,706, according to the Korea Centers for Disease Control and Prevention (KCDC). Thursday's daily tally marks the first time that the country's daily virus cases surpassed the 400 threshold since March 7.

Amid growing calls for measures to prevent the expected shortage, health authorities conducted on-site inspections of hospitals in the metropolitan area earlier in the week and said they will secure more beds in consultation with major general hospitals.

However, only 1,038 out of 3,260 beds, or 31.8 percent, in medical facilities and community treatment centers for COVID-19 patients with mild symptoms across the country were vacant as of Wednesday.

In the metropolitan area including Seoul, the surrounding Gyeonggi Province and the western port city of Incheon, only 444 beds, or 21.9 percent of the total, were available for admission.

A serious problem is hospital rooms for COVID-19 patients with severe symptoms that provide treatment facilities such as oxygen treatment.

Only 62 out of 519 such rooms, or 11.9 percent, were vacant, the KCDC said. In the metropolitan area, only 11 rooms in Seoul, three rooms in Incheon and five rooms in Gyeonggi Province are available.

The government earlier said it takes about five days for patients with severe symptoms to be transferred to intensive care units from when symptoms first appear and that about 85 rooms will remain empty for another one week.

The experts, however, said hospitals for critical patients are expected to be fully occupied earlier.

"The situation can get more serious when the bed shortage continues as it can even lead to increased deaths not only from COVID-19 but other illnesses," said Jung Ki-suck, a doctor at Hallym University Sacred Heart Hospital and former head of the KCDC.

To better cope with the surge in the number of the virus patients, municipal authorities of Seoul, Gyeonggi Province and Incheon have been jointly categorizing patients and allocating hospital beds since Friday.

Separately, the central government is operating community treatment centers for mild cases with plans to open four more capable of housing an additional 2,600 patients this week.

As of Wednesday, only 618 people can be admitted to eight centers, which can house 1,744 people. (Yonhap)