Two people in southern England have tested positive for the South African variant of the coronavirus without having any links to people who have traveled recently, prompting "surge testing" to contain the outbreak.
Residents in parts of Surrey, to the south west of London, will now be tested whether they are showing any symptoms or not, the local authority said.
The government said in January it had detected cases of both the South African and Brazilian variants, however they were all linked to travel.
The Surrey Local Resilience Forum said it would carry out a localized "surge testing" program in the Woking area of the county which would help it to closely monitor any community spread of the new variant, and restrict further transmission.
"This is a precautionary measure – the more cases of the variant we find, the better chance we have at stopping it from spreading further," Ruth Hutchinson, Director of Public Health for Surrey, said.
The emergence of more infectious variants in recent months has raised questions over whether vaccines will prove as effective in containing them.