Retailers in England said on Tuesday they were again asking shoppers to wear masks but said they could not be expected to enforce the new law, fearing abuse of their staff.
Governments around the world are urgently scouring databases for recent cases of COVID-19 infections, screening travellers and decoding the viral genomes of the new variant as they try to measure how far it has spread.
Britain has recorded the third case of the newly identified Omicron coronavirus variant, the UK Health Security Agency said on Sunday, adding that the individual, who was no longer in Britain, was linked to travel to Southern Africa.
Six cases of the COVID-19 Omicron variant of concern have been identified in Scotland, the Scottish government said on Monday, adding that public health officials were working to establish the circumstances of the cases.
Britain's health minister Sajid Javid said on Sunday he expected to receive advice imminently on whether the government can broaden a booster shot programme to try to weaken the impact of the newly identified Omicron coronavirus variant.