Health authorities are on alert as COVID-19 cases from overseas are on the rise even as the overall caseload declines.

On Tuesday, 284 imported infections were reported. The tally has continued to rise since exceeding 200 on Saturday. Some 90 percent of overseas cases are the omicron variant.

The city of Seoul reported a record 85 overseas cases on Tuesday. 

The government believes omicron could become the dominant strain as soon as this month, and plans to revise antivirus and medical response measures accordingly.