Supermarkets have been flooded with panic buyers ahead of greater Brisbane's looming lockdown tonight.

Long queues of shoppers waiting to get into at-capacity supermarkets formed soon after Premier Annastacia Palaszczuk announced Brisbane would enter a three-day lockdown from 6pm Friday night after a mutant UK strain of COVID-19 escaped hotel quarantine.

At Coles Fairfield Gardens, the line for the checkout is a two hour wait.

It is a similar scene at Gasworks with massive line ups just to enter Woolworths.

Chemists have limited sales of masks to five per customer.

Inside the supermarkets, it is mayhem.

Shelves are being stripped bare as residents fear the three-day lockdown could turn into 30 days if case numbers explode.

Shopping centres north of Brisbane are busier than the pre-Christmas rush.

Carparks are full and customers are being forced to join long check out lines with supermarkets understaffed to deal with the rush of panic buying.

Toilet paper, face masks, milk and fresh produce are flying off the shelves.

There have been reports of panic buying at major supermarkets across the Redcliffe peninsula.

Frustrated shoppers have taken to social media urging people to just buy what they need.

One woman reported on social media that she spotted one person buying eight packs of toilet paper.

Another said their local bakery had no bread left at all.

Another said the line at the Kippa-Ring Coles was through the aisles and into the dairy section.

Authorities pleaded with people not to panic buy, saying shops were fully stocked.

Originally published as Panic buying explodes as lockdown looms