South Korea reported more than 300 new coronavirus cases for a fifth straight day on Sunday, as officials warned that stricter rules could be imposed if the trend continues to threaten the highly populated capital of Seoul and surrounding areas.

The Korea Disease Control and Prevention Agency (KDCA) reported 330 new daily coronavirus cases as of midnight on Saturday, a drop from 386 reported the day before, a level not seen since August.

Officials warned that unless the number of infections drops substantially, they may raise the level of social distancing regulations.

On Saturday, a KDCA official said the country is at "a critical juncture" and could be facing a large nationwide outbreak that surpasses two earlier waves of infections, if it fails to block the current spread.

Last week, South Korea tightened prevention guidelines ahead of highly competitive annual college entrance exams scheduled for Dec. 3, and Prime Minister Chung Sye-kyun called for all social gatherings to be cancelled.

Bars, nightclubs, religious services and sports events continue to be permitted with attendance restrictions, but that could change if officials impose more social distancing measures.

South Korea has employed an aggressive tracing, testing, and quarantine effort to stamp down outbreaks without imposing lockdowns. But the country has been dogged by a persistent number of small infections, bringing the total number of cases to 30,733 with 505 deaths.