People in part of Essex are being urged to take a coronavirus test when offered, after the South African variant was discovered there.
It is the latest deployment of surge testing in England in a bid to control and suppress the potential spread of virus variants.
Targeted testing will be offered to residents in the CM13 postcode in Brentwood after one case of the South African variant was detected.
People are “strongly encouraged” to accept the offer of a test, whether or not they have symptoms of the virus.
A spokesman for the Department of Health and Social Care (DHSC) said: “Working in partnership with the local authority, additional testing and genomic sequencing is being deployed to the CM13 postcode in Brentwood, Essex, where a single case of the Covid-19 variant first identified in South Africa has been found.”
Surge testing has now been deployed in specific locations across numerous areas in England.
Sequencing of positive PCR tests – swabs that are processed in a laboratory – can take around two weeks, according to Public Health England.
The DHSC has said data on surge testing will be provided “in due course”.