A health worker conducts a COVID-19 test on a citizen at a testing site in front of Seoul Station on May 5. (Yonhap)

South Korea's new coronavirus cases fell Monday, a week after the government lifted the outdoor mask mandate in the latest attempt to return to pre-pandemic normalcy amid a downward trend in COVID-19 cases.

The country added 20,601 new COVID-19 infections, including 19 cases from overseas, bringing the total caseload to 17,564,999, according to the Korea Disease Control and Prevention Agency (KDCA).

The tally is down from 40,064 on Sunday and 39,600 on Saturday.

The daily count tends to fall on Mondays due to fewer tests on the weekend before rising toward the end of the week.

The public health agency reported 40 COVID-19 deaths, bringing the total to 23,400, the KDCA said. The fatality rate stood at 0.13 percent.

The number of critically ill patients came to 421, little changed from 423 a day earlier.

Last week, South Korea lifted the outdoor mask mandate, except for large gatherings of 50 or more.

Family and religious gatherings increased last week as Children's Day fell on Thursday, and Parents' Day and Buddha's Birthday on Sunday.

Daily infections have been on the downward trend in recent weeks after peaking at over 620,000 in mid-March amid the spreading omicron variant.

Of the locally transmitted cases, Seoul on Monday reported 2,715 new cases and Gyeonggi Province surrounding the capital identified 5,485 cases.

As of midnight Sunday, 44.56 million people, or 86.8 percent of the 52 million population, had been fully vaccinated, according to the KDCA data.

A total of 33.18 million people had received their first booster shots, representing 64.7 percent, and 2.88 million people, or 5.6 percent, had their second booster shots. (Yonhap)