A total of 101 coronavirus cases have been linked to a nightclub cluster in South Korea, Seoul Mayor Park Won-soon said today.

The cluster emerged in the capital’s Itaewon entertainment district over the past few days, raising fears of a second wave of infections.

So far 7,272 people in Seoul have been tested in relation to the nightclub cluster, Park said.

“More than 36% of cases are asymptomatic and the rate of spread is very high,” he said, warning that there had been multiple cases of secondary infection.

An estimated 10,905 people were in the vicinity of Itaewon clubs last week, according to phone signal tower records. The city sent a text message to all the numbers identified and asked them to be tested. The number of people getting tested doubled after officials began offering anonymous testing, Park said.

The city also secured a list of nearly 500 people who were in the affected area through credit card records, and asked them to be tested and to self-quarantine.

Seoul is now conducting random checks of clubs, and entertainment venues to enforce a closure order, Park said.

Second wave: South Korea has been heralded internationally as an example of a country that got its coronavirus response right, largely containing the outbreak through aggressive testing, quarantining, and contact tracing measures.

But the World Health Organization warned yesterday that countries lifting restrictions, including South Korea, saw an uptick in new cases over the weekend.