The new cases took the total in the latest outbreak to 15 so far, a day after the state announced a snap three-day lockdown in Brisbane, Australia’s third-most-populous city.

All of the cases were linked to two distinct virus clusters, one related to a doctor and the second to a nurse, authorities said.

“The fact that we have these cases that are linked is good news,” Queensland State Premier Annastacia Palaszczuk told reporters. “Do we expect to see more cases? Probably. Probably, we will see more.”

About 2 million people in Brisbane are required to stay home until Thursday afternoon except for essential work, healthcare, grocery shopping or exercise while masks are mandatory when stepping outside of homes.

The snap lockdown has thrown the travel plans of thousands into disarray as the lockdown is scheduled to end just a day before the Easter long weekend and the school term break in Australia, a popular time for vacations.

Neighbouring New South Wales (NSW) state, Australia’s most populous, is also on alert after two of the Queensland cases, a nurse and her sister, travelled while infectious to Byron Bay, a tourist town just south of the Queensland border and home to Hollywood A-listers such as Chris Hemsworth.

Health alerts have been issued for some pubs, cafes and restaurants exposed to the virus as officials urged patrons to test and isolate.

“I hope that we do not have any cases emerge in New South Wales, but I won’t be surprised if we did. So, we need to brace ourselves,” NSW Premier Gladys Berejiklian said.

Snap lockdowns, social distancing rules and speedy contact tracing systems have helped Australia to contain fresh clusters in recent months. It has reported just under 29,300 cases and 909 deaths since the pandemic began.