CANBERRA (BLOOMBERG) - Australian hoarders, who have stripped shop shelves of everything from flour to disinfectant and brawled over toilet paper, were shamed by Prime Minister Scott Morrison as the nation's biggest supermarket chain tightened purchase limits during the coronavirus outbreak.

The virus has fuelled panic shopping worldwide by families fearing a months-long lockdown.

In Australia, initial caps on a few essentials proved insufficient and have failed to stop chaos in stores across major cities. Footage this month of three woman fighting in a supermarket in New South Wales state went viral.

"It's been one of the most disappointing things I've seen in Australian behaviour in response to this crisis," Mr Morrison said at a press conference Wednesday.

"It's ridiculous, it's un-Australian and it must stop. I can't be more blunt about it. Stop hoarding."

Shoppers at Woolworths Group Ltd stores can now only buy two items of most packaged goods such as coffee and cereal, the company said on Wednesday.

That's in addition to one-pack limits on products like toilet paper and baby wipes.

Customers can still buy as much fresh fruit and vegetables as they want.

Shares in Woolworths soared 15 per cent through Tuesday after the World Health Organisation last week declared the coronavirus outbreak a pandemic.

Coles Group Ltd, the second-largest supermarket chain in Australia, jumped 17 per cent in the same period.

Woolworths fell 1.4 per cent and Coles fell 2 per cent as of 1.47pm in Sydney on Wednesday.

Coles has so far limited only toilet paper to one pack per customer.

The company has two-item caps on goods such as pasta, flour and rice, though it says additional limits will follow on certain products.