WELLINGTON, New Zealand — New Zealand’s first coronavirus outbreak in six months has grown to seven people.

The announcement Wednesday came a day after Prime Minister Jacinda Ardern imposed a strict lockdown after the first case was reported. The lockdown is for at least three days for the country and at least a week for the cities of Auckland and Coromandel.

Ardern said Wednesday the government expects the number of cases to keep growing, especially after some of those infected spent time at a church, a school, a casino and a hospital. She announced a new mandate compelling people to wear masks in supermarkets, gas stations and pharmacies during strict lockdowns.

Ardern says genome testing has confirmed the outbreak is of the delta variant and originated from an outbreak in Sydney, Australia, although it’s not yet clear how the virus breached New Zealand’s border quarantine controls.