Authorities restricted movement and tightened curbs on gatherings in Australia’s biggest city on Wednesday, hoping to avoid a coronavirus “super spreader” event during New Year’s Eve celebrations after finding a new cluster of infections, according to Reuters.

Household gatherings were limited to five people while the maximum number of people allowed to gather in public in Sydney was capped at 30. Residential care facilities were closed to visitors.

“We don’t want New Year’s Eve to be the cause of a super-spreader,” New South Wales state Premier Gladys Berejiklian said, as she announced the restrictions would take effect from midnight on Wednesday until further notice.

Berejiklian reported 18 new coronavirus cases on Wednesday, the biggest daily increase in a week, with nine of them part of an outbreak in the city’s northern beaches that has grown to more than 100 people over the past week.