Queensland will close its borders from 2pm NZT today to residents of 77 Sydney suburbs after Premier Annastacia Palaszczuk declared them coronavirus hot spots.
Residents of the Liverpool and Campbelltown local government areas will be barred from freely crossing the border, along with all of Victoria.
The move comes as Victoria recorded 270 new coronavirus cases in the past 24 hours. Of those, 28 of those are connected to known and contained outbreaks and 242 of those are under investigation.
A Queensland Health spokeswoman told NCA NewsWire anyone who had been in those areas and was not a Queensland resident would be turned around at the border, while residents would be forced to quarantine in a hotel at their own expense for two weeks.
Chief Health Officer Jeanette Young said the decision had been made as community transmission of the virus spikes in NSW following an outbreak at the Crossroads Hotel at Casula.
"As of midday today, I've now declared Campbelltown City and Liverpool City are both hot spots, which means anyone who has been in those areas in the last 14 days and comes into Queensland will need to go into mandatory hotel quarantine," she said.
The outbreak of coronavirus cases at the Crossroads Hotel has led to 21 cases so far, 11 of those being close contacts of people who attended the pub.
Palaszczuk said the hotel is a "popular pit stop for people travelling the highway, especially truckies".
"We're asking any Queenslanders who visited there between July 3 and July 10 to immediately self-isolate and arrange a Covid-19 test as soon as possible."
So far, 18 Queenslanders who visited the Crossroads have been tested and are self isolating.
In Victoria, there are fears of a major police outbreak after a second officer at a busy Melbourne station tested positive. Dozens of officers are now in isolation.
The officer based at the Frankston Police Station in the city's south-east returned the positive result on Sunday and the station was temporarily closed for a deep clean. Authorities are no tracing his contacts over the past two weeks.
The Campbelltown LGA is comprised of 35 suburbs, which house more than 170,000 people.
These suburbs include:
Airds, Ambarvale, Bardia, Blair Athol, Blairmont, Bow Bowing, Bradbury, Campbelltown, Claymore, Denham Court, Eagle Vale, Englorie Park, Eschol Park, Gilead, Glen Alpine, Glenfield, Holsworthy, Ingleburn, Kearns, Kentlyn, Leumeah, Long Point, Macquarie Fields, Macquarie Links, Menangle Park, Minto, Minto Heights, Raby, Rosemeadow, Ruse, St Andrews, St Helens Park, Varroville, Wedderburn and Woodbine.
Liverpool LGA is made up of 42 suburbs, with 204,326 residents as of the 2016 Census.
These suburbs include:
Ashcroft, Austral, Badgerys Creek, Bringelly, Busby, Carnes Hill, Cartwright, Casula, Cecil Hills, Cecil Park, Chipping Norton, Denham Court, Edmondson Park, Elizabeth Hills, Greendale, Green Valley, Hammondville, Heckenberg, Hinchinbrook, Holsworthy, Horningsea Park, Hoxton Park, Kemps Creek, Len Waters Estate, Leppington, Liverpool, Luddenham, Lurnea, Middleton Grange, Miller, Moorebank, Mount Pritchard, Pleasure Point, Prestons, Rossmore, Sadleir, Silverdale, Voyager Point, Wallacia, Warwick Farm, Wattle Grove and West Hoxton.