Surge testing for the South African variant of Covid-19 is being expanded in several areas across England.
The tests will take place in areas of Norfolk, Southampton and Surrey. Surge testing for a mutation of the Kent variant will also expand in Manchester.
People in the latest targeted areas should take a test this week whether they are showing symptoms or not, the Department of Health (DoH) said.
Surge testing for the South African variant began on 1 February.
At that stage, residents across Surrey, London, Kent, Hertfordshire, Southport and Walsall were asked to take tests, regardless of symptoms.
The DoH said additional surge testing and genomic sequencing would now be deployed to the following postcode areas:
- IP22 in Norfolk
- SO15 5 in Southampton
- GU22 in Woking
- M40 and M9 in Manchester
A government spokeswoman said people with symptoms should book a test in the normal way, while those without symptoms should visit their local authority website for more information.
Surge testing is the roll-out of additional community testing to help reduce the spread of infection by finding asymptomatic cases and prompting people to self-isolate.
Positive cases will be sequenced for genomic data to help scientists and public health officials understand the variant and its spread.
The DoH said surge testing in parts of the London boroughs of Haringey and Merton, along with Sefton in Merseyside, were complete.
"Further data on surge testing will be provided in due course," a spokeswoman said.