It is understood Victorian ministers and public health officials are holding meetings on Thursday to discuss how long the lockdown will last.

An announcement is expected to be made by Premier Daniel Andrews on Thursday afternoon.

It will be the fifth lockdown for Victoria since the start of the pandemic and the third in 2021.

It comes after Victoria recorded two new COVID-19 cases – an adult and a child who attended an AFL match between Carlton and Geelong at the MCG on Saturday.

The two cases are in addition to 10 locally acquired infections recorded in the 24 hours to Thursday morning, all of which were previously reported.

It follows Premier Annastacia Palaszczuk’s decision to keeping masks mandatory in Greater Brisbane for another week to help protect the community from any outbreak after three new cases were recorded in Queensland.

The three new cases are likely unrelated to recent outbreaks in the state – two are suspected to be the result of a Sydney hotel quarantine breach – prompting Chief Health Officer Jeannette Young to order masks remain for another week.

Restrictions were due to be eased at 6am Friday but Young said contact-tracers needed time to track the movements of the new cases and isolate all close contacts. Only Townsville and Palm Island will have restrictions lifted as planned tomorrow.

With a more dire situation in Sydney, and now also in Melbourne, Palaszczuk repeated her call for Queenslanders to reconsider travel to NSW and Victoria and come home if possible.

“We are seeing these little spot fires happening across the nation,” Palaszczuk said.

Under the restrictions, visitors will also remain barred from entering hospitals, aged care and disability services, and social distancing provisions will stay in place, in the Brisbane, Moreton Bay, Ipswich, Logan City, Redlands, Sunshine Coast, Noosa, Somerset, Lockyer Valley, Scenic Rim and Gold Coast council areas.

Victoria’s COVID-19 Commander Jeroen Weimar said the two new cases in that state appear to be linked to an infectious Maribyrnong man who attended the same MCG match and was seated in the member’s reserve on level 2.

But he said the duo were not known contacts of the infected man and it appeared to be a case of “stranger-to-stranger transmission”.

“They were sitting in very different parts of the ground. There’s no obvious relationship between them. The interviews and discussions are ongoing,” Mr Weimar told reporters.

The infected man, aged in his 60s, attended the game with his friend, a teacher from Bacchus Marsh Grammar school who lives in Barwon Heads.

The teacher and two of his family members, a nine-year-old child and a man in his 60s, have also subsequently tested positive for COVID-19.

Both Bacchus Marsh Grammar and Barwon Heads Primary School have been closed and more than 3500 students and staff are self-isolating.

The child who tested positive on Thursday is understood to have attended St Patrick’s Primary School in Murrumbeena, which has also closed.

The Maribyrnong man lives at the Ariele Apartments complex, where removalists from NSW, who have since tested positive to COVID-19, were working on July 8.

Another chain of community transmission occurred at Craigieburn Coles on Saturday, when a man contracted the virus after speaking to a member of a family that had recently returned from NSW.

The family of four have all progressively tested positive since Sunday. They live in the local government area of Hume and were granted a red zone permit to return from NSW.

Weimar said there were 16 active COVID-19 cases connected to the two chains of transmission and more than 75 exposure sites.

“This is probably the fastest response we have ever seen to an outbreak that’s moving more quickly than we have ever seen in Victoria, or I suspect anywhere else in Australia,” Weimar said.