Covid-19 levels in England have risen for the first time in five weeks, suggesting the virus is once again becoming more prevalent.
Infections had been on a downward path since the start of the year, following a surge in the run-up to Christmas.
But there are signs this trend has gone into reverse, with the number of people in hospital with Covid-19 also starting to climb.
Not all parts of the UK are seeing an increase, however.
Infections are continuing to fall in Northern Ireland, while the picture is unclear in Scotland and Wales.
A total of 1.02 million people in private households in the UK were likely to have Covid-19 in the week to January 31, up 8% from 941,800 the previous week, according to the Office for National Statistics (ONS).
Infections peaked at 3.0 million at the end of December, though this was well below the levels reached in previous waves, including in spring 2022 when the weekly total climbed to a record 4.9 million.
Around one in 65 people in England is estimated to have the virus, up from one in 70.
The virus is least prevalent in Wales, at one in 85 people – the lowest estimate for the nation since early September 2022.
For Scotland, the estimate is one in 65, while for Northern Ireland it is one in 70.
Michelle Bowen, ONS head of health surveillance, said the data shows “a mixed picture across the UK”, adding it is “too early to say if these changes mark an overall change in recent trends in infections we’ve seen.”
The ONS infection survey is the most reliable measure of the prevalence of coronavirus and is based on a sample of swab tests from households across the country.