Australia's virus-hit Victoria state reported a major drop in new coronavirus cases Thursday, but officials warned against complacency amid a "worrying" spread of the disease in regional areas outside Melbourne.

Just 278 new cases and eight deaths were detected in Victoria Thursday -- a low not seen in weeks -- while a smaller outbreak in neighbouring New South Wales produced 12 additional cases and one death.

The surge in Melbourne, the capital of Victoria and Australia's second-biggest city, had pushed daily infection rates over 700 in recent weeks.

Dozens have died during a second wave that struck after Australia appeared to have the epidemic in check.

There are now signs that strict measures -- including an overnight curfew and shutdown of non-essential businesses -- are bringing the outbreak under control, but Victoria Premier Daniel Andrews said authorities were "not getting in any way ahead of ourselves".

"We would just caution against any Victorian thinking that we aren't in the midst of a real marathon -- this is an endurance race and we need to stay the course on this," he told reporters.

"We need to be vigilant each and every day."

There are signs that Melbourne's strict measures, including a shutdown of non-essential businesses, are bringing the outbreak under control
There are signs that Melbourne's strict measures, including a shutdown of non-essential businesses, are bringing the outbreak under control AFP / William WEST

Andrews said health officials were launching a new testing blitz in three major regional towns -- Ballarat, Geelong and Bendigo -- amid "worrying trends" indicating the virus could be spreading among residents.

All of regional Victoria is currently under Stage 3 rules, meaning their movement is restricted and wearing a mask is mandatory.

But deputy chief health officer Allen Cheng said authorities were looking "very closely" at whether to increase restrictions to match Melbourne's tough Stage 4 lockdown.

The state remains effectively sealed off from the rest of the country, with other regions so far largely spared from new infections.

Unemployment data released Thursday showed the easing of restrictions across most of Australia saw tens of thousands of people return to work, with the official jobless rate climbing just 0.1 percent to 7.5 percent.

However, the Australian Bureau of Statistics warned the impact of Melbourne's Stage 4 lockdown would not become clear until next month, when economic analysts expect a sharp dip in employment.

Overall, Australia has recorded more than 22,000 cases of COVID-19 and 361 deaths during the pandemic.