The risk level for COVID-19 in the country last week has been assessed as the highest of the government's five-tier scheme.

After evaluating the nationwide risk level as "high" for six consecutive weeks, the Central Disease Control Headquarters raised it up a notch to "very high" in response to developments recorded between February 27 and March 5.

The region-specific risk levels for both the capital region and the rest of the country were also raised from "high" to "very high.”

The five-tier system measures infection risks based on 18 factors, including ICU bed occupancy, the number of critically ill patients and the percentage of people aged 60 and older among the caseload.

Meanwhile, the detection rate of the omicron variant has reached 100 percent among local transmissions and 99-point-two percent among cases from overseas as of Saturday.

Detection of the subvariant BA.2, known as the "stealth omicron," accounts for 22-point-nine percent of domestic cases and over 47 percent of imported cases so far.