New Zealand’s government has extended a lockdown of its largest city Auckland for another 12 days as it tries to stamp out its first domestic coronavirus outbreak in more than three months.

The outbreak has grown to 30 people and extended beyond Auckland for the first time. Until the cluster was discovered Tuesday, New Zealand had gone 102 days without infections spreading in the community, with the only known cases travelers quarantined after arriving from abroad.

Prime Minister Jacinda Ardern says extending the lockdown will give health authorities time to get a handle on the cluster and isolate those infected.

According to Johns Hopkins University data, New Zealand has had 1,600 confirmed COVID-19 cases, the vast majority coming in March. The 1,600 cases resulted in 22 deaths.