Residents in Victoria's coronavirus hot spots have been told to abide by travel restrictions even if they leave their suburbs ahead of tighter lockdowns.
On the day before more than 30 suburbs head into localised lockdowns, Victorian Premier Daniel Andrews on Wednesday urged residents to stay home to avoid fines.
Conceding the targeted lockdown raised many questions, Mr Andrews urged Victorians from hot spots to stay put, even if they left the suburbs for work.
"Because this is not statewide, there will be some additional complexities ... the alternative is to lock down the whole city or the whole state," he told reporters on Wednesday.
"If you're out and you can't explain yourself ... then you face the very real risk of 'a' being caught, and 'b' being fined."
Police Minister Lisa Neville said patrols will be increased on the boundaries of affected suburbs, and officers will block roads to check on people entering and leaving.
Ms Neville foreshadowed a likely shift from warnings to fines from Thursday, with more fines expected to be issued in most hot spots.
New South Wales on Wednesday announced Melbourne residents of COVID-19 outbreak areas who seek to enter the state could face six months' jail or an $11,000 fine.
"Victorians living in virus hot spots have to take the Victorian and NSW health orders seriously and should be very aware that NSW will impose penalties if they seek to leave hot spot suburbs," NSW Health Minister Brad Hazzard said in a statement.
Opposition leader Michael O'Brien said suburbs were locked down because there was a failure of competence and leadership from Mr Andrews.
"Hotel quarantine has been a disaster only in Victoria," he said.
Mr Andrews on Wednesday said genomic sequencing had traced a big proportion of coronavirus cases to breaches in hotels hosting returned travellers.
Victoria recorded 73 new coronavirus cases on Wednesday.
Three of the cases are from hotel quarantine, nine are associated with known and contained outbreaks, 19 were found through routine testing and 42 remain under investigation by the public health team, Mr Andrews said.
The majority of Victoria's new cases are due to community transmission, prompting Mr Andrews to reintroduce stay-at-home orders for 10 postcodes from Thursday until at least July 29.
Those postcodes are: 3038, 3064, 3047, 3060, 3012, 3032, 3055, 3042, 3021 and 3046.
Much like earlier stage three restrictions, residents of the postcodes will only be able to leave their homes to shop for food and supplies, to receive or provide care, to exercise, and to study or work if they can't do so from home.
Residents of those suburbs have been urged to get tested to help contain the virus.
About 54,000 homes have been reached and 113,000 people tested in the week since a doorknocking information blitz started in Melbourne's northern and western suburbs following the outbreak.
"There will be 12 new sites that will be dedicated testing locations across all of those postcodes that have been locked down from midnight tonight," Mr Andrews said on Wednesday.
"This is not over. It won't be over for a long time and the best and most important thing that we can all do, whether we are in one of these hot spot postcodes or not, is to follow the rules."
Victoria is receiving clinical support from other states to help its fight.
Thirty clinical staff are coming from South Australia and about 40 Queensland nurses are on their way.
NSW, Queensland, WA, SA and Tasmania are also providing contact tracing and pathology help.
Twenty-two fixed-site, drive-through and mobile testing sites are already operational.
Australian Associated Press
