Queensland will plunge into its strictest lockdown ever after the state recorded six new Covid cases.
It comes a day after Indooroopilly State High School in Brisbane's inner west was forced to close for a specialist deep clean while Queensland Health performed contact tracing on a Covid positive schoolgirl and her family.
Queensland Health Minister Yvette D'Ath confirmed the case at the school of 2,500 students at Friday morning's Covid update.
'She became unwell yesterday and went and got tested and overnight her result has come back positive,' she said.
'We are testing her family members. It's a family of five. They live a at Taringa. She's been in the community for three days and at school for two days.'
A 17-year-old senior school student from Indooroopilly State High School in Brisbane's inner west felt unwell yesterday and returned a positive test early on Friday morning
The unlinked case at Indooroopilly State High School saw the school closed for 48 hours to undertake deep cleaning (above) as contact tracers worked to find the source of the infection
Indooroopilly State High School is a major Brisbane high school, educating around 2,500 students
Queensland's chief health officer Jeannette Young described the new case as 'quite concerning' as health authorities scrambled to identify its source
'This is an unknown, unlinked case at this stage,' Ms D'Ath said. 'Until we get more information, masks are more important than ever,'
An email from Acting Principal Derek Weeks to parents early on Friday morning alerted them to the case and the closure of the school for 48 hours.
'I am writing to let you know that a person associated with our school community has been diagnosed with Covid-19,' Mr Weeks's email read.
'As a result, our school will be closed effectively immediately for 48 hours to allow for Queensland Health to perform this contact tracing and, as an extra precaution, I have arranged for specialist cleaners to come to perform a deep clean in accordance with Queensland Health guidelines.
'I will continue to liaise with the department and we will continue to take the advice from Queensland Health.'
The acting principal urged anyone feeling unwell or displaying symptoms of the virus to immediately consult their GP.
The Springfield campus of the University of Southern Queensland was also closed for precautionary cleaning late Friday morning as a result of the Indooroopilly State High student's positive test.
Students of the university and the school had collaborated earlier this week.
A community vaccination centre in the Nicholas Street Precinct at Ipswich was also closed until further notice after the Indooroopilly student visited the clinic yesterday.
Queensland chief health officer Jeannette Young said the school case was 'quite concerning'.
'I'm struggling to understand how she's acquired it,' she said. 'So we'll have to wait until we get whole genome sequencing results back later today to be able to work out where she's got this from.'
'If this girl was a close contact we would have expected to hear by now,' Alex, a parent of two daughters at the high school, told ABC Radio on Friday morning. 'We don't know anything at this stage.'
Yesterday, Queensland's mask mandate was extended a further week due to a number of 'incursions' of the virus into the state.
Earlier this week it was announced a man who tested negative three times in hotel quarantine later returned a positive test after being infectious in the community in Brisbane for six days.
He stayed at a backpacker hostel in Brisbane before becoming unwell and getting tested last Monday.
Anyone who stayed at Joe's Place Backpackers and Brisbane City Backpackers from the afternoon of July 20 to 1am July 28 were considered close contacts.
A pop-up drive-through Coronavirus testing facility is seen at the Centrepoint Church in Taigum, Brisbane this week. Queensland's mask mandate will continue another seven days after recent 'incursions' of the virus into the state