U.K. Prime Minister Boris Johnson on Saturday imposed a new round of restrictions for London and much of southern England after officials said they have identified a new COVID-19 strain that can spread more quickly and is believed to be linked to a rise in infections across those areas. 

Johnson said that the capital and other areas in southern England currently under Tier 3 -- the highest level of coronavirus restrictions -- will move to an even stricter new Tier 4 that requires non-essential shops, hairdressers and indoor leisure venues to close after the end of business hours Saturday. 

source: https://www.foxnews.com/world/uk-tier-4-lockdowns-new-covid-strain-surge-cases