South Korea has two main concerns. First that the outbreak is in the highly populated greater Seoul area, and secondly that the cluster involves yet another highly secretive church and hundreds of members have provided false contact details at gatherings.

Let's not forget, South Korea has been in this position before and prevailed. Its highly efficient track-and-trace system, paired with multiple testing facilities, has brought cluster outbreaks under control.

But Sarang Jeil church members rallied in the centre of Seoul at the weekend, ignoring warnings from health officials that they risked spreading the virus.
Domestic media has also shown footage of church members shouting and swearing at virus contact tracers. It seems some of them believe that this is part of a conspiracy to close the right-wing church, which is highly critical of President Moon's administration. They are also reluctant to comply with quarantine orders or get a test.

Authorities have the power to introduce stricter social distancing guidelines and they have shut down facilities such as karaoke rooms and nightclubs. Most companies based in Seoul have also told their employees to work from home.

But tracking down reluctant church members who are most at risk of catching and spreading the virus may prove more difficult.