The number of daily new COVID-19 cases in South Korea jumped about tenfold to nearly 300 recently amid the rapid spread of the coronavirus across the nation.

According to the Central Disaster and Safety Countermeasures Headquarters on Sunday, the daily average of new infections in the two-week period from August 16 to 29 came to 299-point-seven, compared to 35 for the previous two weeks.  

The proportion of untraceable cases nearly doubled to 19-point-four percent over the cited period. However, in the past week, the ratio jumped to a record 24-point-nine percent.

Authorities said the soaring cases and rising proportion of untraceable cases are posing a challenge to health authorities' efforts to trace and isolate potential infections. 

Additionally, they called for citizens' active cooperation in the enhanced social distancing guidelines in the greater Seoul area until next Sunday.