Hong Kong is seeing COVID-19 cases climb again, with the number of new infections at a six-week high amid a growing cluster that originated at a group of nightclubs in the financial hub’s Central district.

The city reported 515 cases on Sunday, the most since April 23. More than 200 cases have been linked to the outbreak associated with four bars, thought to have emerged after the latest round of social-distancing curbs were loosened about a week ago. The cases have been linked to Shuffle nightclub in Lan Kwai Fong, as well as Zentral, LINQ and Iron Fairies, all located in Hong Kong’s Central district.

The clusters are most likely to be the predominant BA2.2 strain, the city’s health official said. Centralized quarantine is enforced for those carrying nonprevalent BA2.2 subvariants.