Queensland has woken to the first day of their three-day lockdown, as the state recorded nine new locally acquired cases of COVID-19 overnight, in addition to the six cases recorded yesterday.
This is the highest number of local cases for Queensland in the past 12 months. All new cases are confirmed to be of the Delta strain.
There are 11 local government areas in southeast Queensland who have been plunged into the snap lockdown. The LGAs are: Brisbane, Ipswich, Logan City, Moreton Bay, Redlands, Sunshine Coast, Gold Coast, Noosa, Somerset, Lockyer Valley and Scenic Rim.
Here's what you need to know about the snap lockdown.
How did the Queensland outbreak start?
The index case of this outbreak is a 17-year-old high school student from Brisbane's inner-west who tested positive on Thursday.
The student's two parents and two siblings have also tested positive, as well as a medical student who tutors the girl. A staff member of lronside State School, which the family's youngest child attends, has also tested positive.
However, this is still no known link between these positive cases and the origin.
Queensland's Chief Health Officer Dr Jeannette Young said genome sequencing has linked the high school student's infection to two people who are in hotel quarantine after returning from overseas. But they don't know how COVID-19 transmitted between them.
"I don't know where this virus is at the moment," Dr Young told reporters on Sunday morning. "Please come forward [for testing]. Because then we will be able to find those other chains of transmission which I expect are out there."
Dr Young is particularly concerned about Sunshine Coast, saying she believes there are unknown cases in the community.