TESCO and Asda yesterday became the latest supermarkets to take a tougher stance on customers who refuse to wear a face covering without a medical exemption.
The two supermarket chains said it would ban shoppers who refuse to wear a face covering without a valid medical reason and also appealed to customers to be respectful to staff.
It comes after Sainsbury's had earlier announced it would enforce mask-wearing and shopping alone in its stores.
It said it would have trained security guards at the entrances to its stores to challenge those shopping in groups or not wearing a face covering.
Face coverings are currently mandatory in shops and other enclosed places in Northern Ireland.
Tesco yesterday said it "won't let anyone into our stores who is not wearing a face covering, unless they are exempt in line with government guidance".
"We are also asking our customers to shop alone, unless they're a carer or with children," a spokesman said.
"To support our colleagues, we will have additional security in stores to help manage this.
"Our colleagues are working hard in difficult circumstances to make sure everyone can get what they need and we'd ask everyone to please be kind, patient and respectful as we all work to keep each other safe."
Asda has also said "safety marshals" are being deployed in its stores to clamp down on those not wearing face coverings.
Echoing Tesco's calls for customers treat staff with respect, an Asda spokesman said: "If a customer has forgotten their face covering, we will continue to offer them one free of charge.
"But should a customer refuse to wear a covering without a valid medical reason and be in any way challenging to our colleagues about doing so, our security colleagues will refuse their entry."
