South Korea saw an uptick in the daily average number of COVID-19 cases for the third consecutive week, since the country lifted most of its antivirus restrictions in mid-October, as health authorities are on alert over a post-Halloween weekend surge in infections.

Korea reported 97 new coronavirus cases -- 79 locally transmitted and 18 imported from overseas -- in the 24 hours ending Sunday at midnight, according to the Korea Disease Control and Prevention Agency.  

Halloween is a major concern for health officials as the country saw popular nightlife spots like Seoul’s Hongdae, Itaewon and Gangnam packed with young people over the weekend. The impact of such gatherings will likely be seen in the coming days.

“In the situation where the risks of virus transmission were heightened due to increased contacts among people through events, gatherings and trips, there are concerns that more people will get exposed to enclosed, packed and connected environments as we enter winter,” KDCA Director Jeong Eun-kyeong said in a briefing.

Since the country eased its three-tier social distancing restrictions to the lowest level on Oct. 12, the daily tally has fluctuated around 100, with the majority of infections traced to nursing homes, hospitals, a welfare facility, social gatherings and workplaces in the Greater Seoul area.

From Oct. 18-24, the average number of COVID-19 cases per day was 86.9, up 11.6 from the previous week. The proportion of the cases with unknown transmission routes also rose to 13.8 percent during the period, compared with 8.7 percent a week earlier.

Currently, the loosest social distancing rules are in place. Korea’s new five-level social distancing system, designed to better respond to different virus situations in different regions, will take effect Saturday.

In Gwangju, Gyeonggi Province, a total of 22 cases were reported in connection with a family gathering. The first case was reported Saturday.

Twelve more people tested positive for the virus in connection with a workplace in Paju, Gyeonggi Province, bringing the number of related cases to 13. The first case was reported Saturday.

At another workplace in Asan, South Chungcheong Province, 19 cases were reported. The first case was detected Friday.

Of Monday’s locally transmitted cases, the majority were in Greater Seoul -- 20 in Seoul, 40 in Gyeonggi Province, which surrounds the capital, and two in Incheon. Eleven cases were reported in South Chungcheong Province, three in Daegu, two in South Jeolla Province and one in North Chungcheong Province.

Korea reported 18 imported cases. Among them, 11 were identified while the individuals were under mandatory self-quarantine in Korea, with the other seven detected during the screening process at the border. Eleven cases were from elsewhere in Asia, four were from Europe and three were from the Americas. Twelve of those cases involved foreign nationals.

The number of COVID-19 patients in serious or critical condition here reached 49.

Two more people have died from the virus, bringing the death toll to 468. The overall fatality rate is now 1.75 percent.

So far, of the 26,732 people confirmed to have contracted the new coronavirus here, 24,395 have been released from quarantine upon making a full recovery, up 38 from a day earlier. Some 1,869 people are receiving medical treatment under quarantine. 

The country carried out 6,020 tests in the past day. A total of 25,524 people were awaiting results as of Monday.

By Ock Hyun-ju (laeticia.ock@heraldcorp.com)