Surge tests are taking place in two postcode areas of London after cases of the South African variant are identified.
The Department of Health and Welfare (DHSC) announced that additional testing and genome sequencing will be carried out in postcodes SW11 and SW15 in parts of Wandsworth, southwest London.
Officials say improved contact tracing will be used for people who test positive with a worrying variant.
During this process, tracers look back over a long period of time to determine the transmission path.
The additional tests will be introduced in addition to the existing extensive tests. According to official figures, this will help monitor and suppress the spread of the virus.
All positive Covid cases that are found will be sequenced for genomic data to improve understanding of the coronavirus variants and how they spread.
The DHSC said residents of the target areas were “strongly encouraged” to take a test, if offered, even if they did not show symptoms.
Those who have symptoms should book a free test online or by phone so they can be tested at a testing site or have a test kit sent to their home.