Shoppers say a supermarket's move to convert almost all of its tills to automated machines has led to "total carnage" at the checkouts.

Some customers at Sainsbury's in Maidstone are angry after just four tills operated by staff members were left following a recent overhaul.

The town centre store, in Romney Place, previously had 26 manually operated checkouts but these have almost all been removed to make way for 24 automated machines.

The change came into force last week and was met with a barrage of criticism from frustrated shoppers.

Lynn Brownson, a retired care worker, 68, who shops at the store once a week, said: "I don't like them, they keep going wrong and I have to wait for someone to come and fix it again for me.

"If you move a bag it goes wrong – I think they should stop it."

Roger Pinder, a retired printer, 70, said: "I had a bit of trouble with it. I didn't know if I had paid or not with the card."

Others took to social media to vent their frustrations and complained about long waiting times for certain items to go through the system.

Matthew Scott said: "I hate them. If you buy most kinds of medicine, alcohol or any age-restricted item, you need it approving.

"Now whilst this is the same at a normal checkout, it's all done at the end. With self-checkouts, you're always waiting because they have one member of staff trying to manage 12 tills.

"Not to mention every other item making the scales freak out."

Maria Cooper added: "It was total carnage in there when I went at around midday. There was just people lining up in massive long lines all around the shop.

"People were just walking out, while some others were getting rather fed up with the tills keep demanding staff assistance and staff not coming quickly."

But not everyone said they were opposed to the changes.

Aneta Tomasiuk said: "I personally think it’s a much-needed change. Self scan or smart shop is the only way I’ve been doing my shopping for ages now.

"It’s a lot quicker and cheaper to use smart shop too, it's brilliant."

Speaking outside the shop, 25-year-old digital designer Danny Potter said: "I love it, it's easier, it's useful and quicker."

Laura Potter, 34, a senior delivery manager, said: "I like them. You can get in and out very quickly and staff are really helpful if there's a problem.

"Sometimes tills are much easier to use if you have a big trolley in rush hour on a Saturday when everyone's coming for their weekly shop."

A Sainsbury’s spokesman said: "We regularly review the services available in our stores to make sure our we offer the most convenient experience to our customers.

"We have slightly increased the number of self-service checkouts at our Maidstone store so that we can meet customer demand for this service.

"Our colleagues are on hand to help anyone who may need support using them, and we continue to offer manned checkouts for our customers who wish to use them."

The first self-checkout machines were designed and patented in the 1990s, but grew to prominence in the early 2000s, with Tesco introducing them in 2003.