Queensland will close its borders to thousands of Sydneysiders after the rapid expansion of the Bondi coronavirus outbreak.

Queensland Premier Annastacia Palaszczuk announced the state would follow Victoria in banning entry to people from seven Sydney local government areas.

COVID hotspots have been declared in Sydney city, Woollahra, Bayside, Canada Bay, Randwick and Inner-West. The declaration takes effect from 1am Thursday, throwing school holiday plans into chaos.

The Waverley Council area had already been declared a hotspot.

“To keep Queenslanders safe, we will be following exactly what Victoria has announced last night,” she said on Wednesday.

“This advice may have to be updated during the course of the day or into the evening,” she said.

“NSW is treating this seriously and we are treating it seriously.”

The number of locally acquired infections in NSW rose to 21 on Tuesday, with 10 more cases confirmed.

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Seven came in after the 8pm cut-off and will be officially included in Wednesday’s numbers, which will be released at 11am (AEST).

NSW Health has also added to the list of venues visited by infected people. They are spread across Sydney, but also include to trans-Tasman flights after confirmation a passenger had been diagnosed with the virus.

NSW authorities are also watching mystery case numbers closely, with Sydney hoping to avoid a lockdown like Melbourne has recently emerged from.

Mandatory mask rules have been extended by a week in Sydney and QR codes will become mandatory in all NSW shops.

Premier Gladys Berejiklian has not ruled out a lockdown but said she had a “degree of confidence” because there was only one infection not linked to a known case.

Queensland had no new community cases on Wednesday after its own scare involving a woman who tested positive after leaving hotel quarantine and a man infected at a Portuguese restaurant.

Ms Palaszczuk also revealed another case of the highly infectious Delta variant of COVID spreading in a Brisbane quarantine hotel.

“We are making sure that we look at that floor closely, and once again we just think it’s probably a case of people opening the doors,” she said.

-with agencies