South Korea’s Joint Chiefs of Staff reported Tuesday the first coronavirus case at its headquarters in Seoul.

A civilian office worker tested positive the previous day, pushing about 20 workers into a two-week quarantine and about 200 employees to take COVID-19 tests.

“The infected employee did not make a trip to the ministry headquarters,” a Defense Ministry official said. The JCS and ministry headquarters sit side by side at the Yongsan compound that houses several key commands.

The ministry said the employee was not one of the staff who will be taking part in the biannual joint military drills between South Korea and the United States, which is planned for the second week of March.

Seoul and Washington, which have held them to deter aggression from Pyongyang since the 1953 Korean War armistice, are preparing to run computer-based war games for nine days.

The two allies skipped the exercises in March last year and scaled back the following drills in August because of the pandemic.

“Every precaution is being taken and we’re closely coordinating with the US on the upcoming event,” the Defense Ministry said. The ministry has reported 561 infections so far, with 218 service members currently in quarantine.

By Choi Si-young (siyoungchoi@heraldcorp.com)