A NATIONAL technical outage halted trading at Woolworths stores, causing chaos for shoppers as their trolleys bank up and some stores temporarily closed.

Registers shut down with stores unable to make sales shortly after 4pm, leaving consumers at Australia’s largest supermarket chain with trolleys full of shopping — but no way to pay.

Signs have been put up at a number of Woolworths stores apologising for the problem, which has been described as a “system fault”.

Social media posts showed shoppers banked up in stores with their trolleys, unable to move.

Others were told to leave the stores. Many left full trolleys behind.

The outage also saw some stores pull their shutters down, but it is understood this was a temporary measure taken to prevent more frustrated customers from coming into stores while the outage occurred.

Shopper Sharni was among those asked to leave her groceries behind at the Hampton Park store in Melbourne.

“It was really frustrating. We were all queued up at the checkout and we were told to leave due to a power outage and I just spent an hour doing my groceries,” she said.

News Corp Australia counted at least ten abandoned trolleys and baskets in the store.

A security guard was also stationed at the closed doors to turn shoppers away.

More than 20 shoppers were reportedly turned away by the security guard.

A woman called Rose, from Hoppers Crossing in Melbourne, told 3AW customers were offered lollies as they were asked to leave.

“Everyone was walking out of the store empty handed. Staff were very apologetic. Staff said every register in every store nation wide has shut down. We were all offered a box of chocolates.”

Shoppers have taken to Facebook across Australia to complain about the outage, accusing the supermarket chain of “ruining dinner plans”.

One woman, Virginia Johnsotne from Sydney posted on Facebook: “Woolworths you are having a laugh...I just spent 45 minutes shopping with 3 kids and your registers go down and you tell me (quite rudely) that I need to leave the store without my groceries. Good customer service would have been to let everyone currently in the store have their trolley load for free. But no....you throw everyone out on school holidays with nothing for dinner. Bad form....I’ll stick to Aldi.”

Woolworths has told News Corp Australia that an IT issue affected registers in about half of their stores this afternoon, but their system was back up online now.

Woolworths has 995 stores across Australia, which means the outage affected close to 500 stores today.

A Woolworths spokeswoman said the registers were coming back online just after 5pm.

“We can confirm that an IT issue impacted registers in our supermarkets for a short period of time this afternoon,” she said.

“The registers are now back online in all our stores​. We apologise for the inconvenience this caused our customers.”

Woolworth confirmed that all stores were now open, even if they had temporarily pulled down their shutters during the outage.

The supermarket’s social media team also confirmed that the IT issues occurred to shoppers who took to Twitter to complain about being unable to buy groceries.

Seven News in Adelaide is reporting that some customers at a Woolworths store in Adelaide’s west got their groceries for free after the nationwide outage.

Woolworths has been approached by News Corp Australia for more details about how the technical glitch occurred and if shoppers will be compensated any further.