A new variant of coronavirus is under investigation in the UK after scientists identified 16 cases.
Public Health England (PHE) has announced that cases of the variant, referred to as VUI-202102/04, were first identified on February 15.
They have been discovered through genomic horizon scanning with the variant understood to have originated in the UK.
PHE said on Thursday that all individuals who tested positive and their contacts have been traced and advised to isolate and said the variant was designated a "variant under investigation" (VUI) on February 24.
The latest findings mean there are now four VUIs and four "variants of concern" (VOC) being tracked by scientists in the UK.
The new identified variant contains the E484K mutation, which is found in two other VUIs present in the UK, but it does not feature the N501Y mutation that is present in all VOCs, PHE said.
Additional testing - known as surge testing - is currently being made available for targeted areas of England to suppress the spread of VOCs.
The Department of Health said on Thursday that two new areas would be offered additional testing as cases of the South African variant of coronavirus has been found.
A DHSC statement said the testing and genomic sequencing was being targeted in the North Wembley area of Brent, north London, and the TS19 postcode area in Stockton-on-Tees, in County Durham.
