SYDNEY, March 16 (Xinhua) -- A fifth person has died in Australia after contracting COVID-19, as the country initiated strict new measures to contain the spread of the virus.

Health authorities in the State of New South Wales (NSW) said a 90-year-old woman having tested positive passed away on Saturday, and that a 77-year-old woman with the disease had died in hospital on Friday after recently arriving from overseas.

The 90-year-old woman was a resident at a Sydney aged care facility which recorded one of Australia's first person-to-person transmissions of the virus at the beginning of the month.

On Monday the total number of confirmed COVID-19 cases in Australia surged past 300, with the worst affected State of NSW posting its biggest daily jump of 37 new cases, taking the state's total to 171.

Over the weekend Prime Minister Scott Morrison announced that as of Monday, all overseas arrivals including Australian citizens would be required to self-isolate for 14 days.

"What we've seen in the recent weeks is more countries having issues with the virus, and that means that the source of some of those transmissions are coming from more and more countries," Morrison said.

"We're seeking to assist Australians to come home by ensuring that the flights continue to run, but when they come home, they'll be spending another 14 days in self-isolation."

NSW State Premier Gladys Berejiklian said the police would have the authority to enforce the isolation measures and encouraged members of the public to report those who don't comply.

"People should report these cases of people turning up to work when they shouldn't. You can let the relevant authorities know and the police can turn up and enforce that person to stay home," Berejiklian said.

A ban on gatherings of over 500 people also came into effect on Monday, bringing into question the viability of the country's sporting leagues which rely on spectator income.

The ban does not directly apply to schools and universities, however a number of festivals, concerts and sporting events were cancelled with more disruptions expected over the coming months.

Meanwhile, the country's largest supermarket chain, Woolworths, offered one hour of special priority shopping to elderly customers and those with disabilities, in the mornings before their stores open to the general public.

Woolworths Supermarkets Managing Director Claire Peters said the practice of some alarmist customers panic-buying bulk goods had caused elderly members of the community to miss out.

"While we'll continue to do our very best to restock our stores during this period of unprecedented demand, we know many of our elderly customers have been missing out on essential items when they shop," Peters said.

"Now -- more than ever -- we need to be kind to each other, especially to those most vulnerable."