MELBOURNE, AUSTRALIA -- Australia has been among the world's most successful countries in containing its coronavirus outbreak -- with one exception.

The southeastern state of Victoria had some of the nation's toughest pandemic measures and was among the most reluctant to lift its restrictions when the worst of its outbreak seemed to have passed.

But as most of the country emerges from pandemic restrictions, the virus has resumed spreading at an alarming rate in Victoria's capital, Melbourne. The city is buckling down with more extreme and divisive measures that have ignited anger and arguments over who is to blame.

Victoria Premier Daniel Andrews said Tuesday that the entire city and some of its surrounds will be locked down again from Wednesday night under tougher restrictions than were imposed during the first shutdown that started in March.

"We are in many respects in a more precarious, challenging and potentially tragic position now than we were some months ago," Andrews said.

About 3,000 residents of nine public housing high-rise buildings were given just an hour's notice at the weekend before being prohibited from leaving their apartments for at least five days.

"The amount of police officers makes us feel like we're criminals," said a resident of one of the buildings, Nada Osman. "It's overwhelming. It's scary. It's like we're caged in."

Forty suburbs that are virus hot spots have been locked down by postal code since last week, with the result that businesses and households in some areas face restrictions while ones across the street from them do not.

"The line has to be drawn somewhere and I think most people can understand that," Maria Iatrou, whose cafe is restricted to takeout because it is on the wrong side of a suburban border, said before the citywide lockdown was announced.

"But that doesn't take away any of the frustration and disappointment associated with having to live with these restrictions again because we're unlucky enough to belong to one of these post codes," she said.

Victoria authorities had been praised for their aggressive testing and contact tracing. Melbourne researchers developed what they describe as the world's first saliva test for the coronavirus, a less accurate but more comfortable diagnostic tool than nasal swabs, in an effort to encourage more people to agree to door-to-door testing.

It's an extraordinary situation that raises questions about how Australia's second-largest city fell so far behind the rest of the country.

The nation of 26 million people has recorded about 8,500 cases and only 106 deaths from COVID-19.

Most if not all the blame is being directed at lax controls at quarantine centres set up in two Melbourne hotels.

Australian citizens and permanent residents returning from overseas are required to spend 14 days in strict hotel quarantine. Genomic sequencing that identities which virus strains are circulating in specific clusters indicates the city's expanding outbreak is emerging from hotel quarantine guards and guests.

Critics of the Victoria government blame a decision to use private security contractors to enforce the quarantine.

Sydney, Australia's largest city, which in the early days of the pandemic had the country's highest number of daily new cases, chose to use police and the military to provide hotel security, with greater apparent success.

Media reports have alleged security firms charged the Victoria government for hotel guards that were not provided and that guards had sex with quarantined hotel guests and allowed families to go between rooms to play cards.

The Victoria government has largely shut down public debate on what went wrong by appointing a retired judge to hold an inquiry. Government officials maintain it would not be appropriate to make public comment before the judge reports her findings on Sept. 25.

But the government acknowledged infection control failures and has changed its system. State prison workers now oversee hotel quarantine and international travellers are no longer allowed to land at Melbourne airport.

Premier Andrews has defended plans to employ grounded Qantas flight crews to work with the prison guards in the hotel quarantine against union complaints that the crews were offered little training.

"There are very few groups of people who take safety more seriously and know and understand safety protocols and dynamic environments and the need to always go by the book than those who work in our aviation sector," Andrews said.

Catherine Bennett, an epidemiologist at Melbourne's Deakin University, said the city could be having similar success as the rest of Australia in virtually eliminating community transmission if not for the hotel quarantine breaches that allowed security guards to bring the virus home to their suburbs.

"We've had multiple positive people take the virus home at the same time into extensive multi-household families just after Victoria had relaxed its restrictions," said Bennett, who lives outside the 40 shutdown suburbs.

"Luck comes into it. You just need one person positive in a setting where it can take off to have a problem. That setting probably exists in cities all around Australia," she said.

Victoria officials wonder how many of Melbourne's residents will continue social distancing during their second lockdown as they see the rest of Australia lift restrictions.

Iatrou said the current lockdown has made a "massive difference" in earnings at her cafe in the suburb of Ascot Vale.

She welcomed the Melbourne-wide shutdown because it put her business back in competition with her competitors in previously unrestricted suburbs.

But time would tell whether business would return to the levels of the first nationwide lockdown.

"People are a lot more scared this time around," Iatrou said.

If customers stayed away though fear of infection or they lacked income, she said: "There'll be a lot more businesses closing their doors by the end of this."

McGuirk reported from Canberra, Australia.