Woolworths has apologised after a technical glitch knocked out thousands of registers across the nation for close to an hour, forcing some stores to shut.

About 500 of the grocery chain’s 995 stores were affected between roughly 4pm and 5pm AEST.

Registers came back online within an hour, a spokesperson confirmed to The New Daily.

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

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

Woolworths is still working to find out the cause of the IT problem, but has ruled out a cyber attack.

On social media, shoppers around Australia said they had been told to abandon their trolleys and leave the store.

“Was in Woolworths when the computers went down – poor staff trying to cope and frantic calls to IT,” Liz Green wrote on Twitter.

At Haymarket, in Sydney, staff shut the store and were turning people away, telling them to “come back in about an hour”, with similar stories emerging across the nation.

Woolworths is Australia’s largest supermarket chain, with close to 1000 stores.

Nationwide IT issues at @woolworths – stuck at the front of the #Malvern queue unable to process any transactions! #woolworths pic.twitter.com/qKZxTKvgaG

— Hannah Walravens (@hannahwalravens) April 16, 2018

ALL #woolworths checkouts have stopped working. UTTER CHAOS NATIONWIDE. pic.twitter.com/3ipU8o0tYF

— Steph Boulet (@StephBoulet) April 16, 2018

Apparently @woolworths registers are… #woolworths pic.twitter.com/1bVv2rIo98

— Claudia Hooper (@claudiquante) April 16, 2018

IT systems failure has crippled #Woolworths stores nationwide; looking forward to the apparently imminent era of the fully automated "driverless car" – what could go wrong?

— Leo D'Angelo Fisher (@DAngeloFisher) April 16, 2018