Shoppers at a Coles and a Woolworths in Queensland are being asked to seek testing for coronavirus and isolate for 14 days immediately.
The public health alert was issued by Queensland Health late on Saturday afternoon.
It comes after someone with COVID attended the Coles in Sunnybank Hills Shoppingtown and Woolworths in Calamvale North.
Fellow shoppers who were there at the same time are considered close contacts.
They should seek testing immediately and quarantine for a full 14 days since they attended the supermarkets.
Customers who were at the Coles between 7.30am and 8am on January 5 or the Woolworths between 11am and midday on January 3 is impacted by the health advice.
Anyone unsure if the advice applies to them should call QLD Health on 13 43 25 84, the health body says.
Greater Brisbane residents will remain in lockdown until 6pm Monday after a hotel quarantine cleaner was diagnosed with the virulent UK strain of the virus.
Other states and territories have placed restrictions on travel to and from Queensland’s capital and surrounding areas.
Meanwhile, the Gabba is still holding onto hope it can keep the Fourth Test of India’s cricket tour of Australia.
Friday’s announcement, when Queensland Premier Annastacia Palaszczuk warned “this is incredibly serious”, won’t affect the rules governing the Australia and India squads if they do land in Brisbane.
“As I said yesterday and the day before, discussions are still happening and they are still positive,” Palaszczuk said on Saturday.
The Test is slated to start on January 15, meaning the prospect of a heaving crowd at the Gabba for the series finale is now essentially over.