Coronavirus infections have increased in recent weeks in England, according to new estimates.
Tests in thousands of households by the Office for National Statistics found a rise in positive tests among young people, but not in those over 50.
Estimates suggest there were 3,200 new cases a day during the first week of September, compared to 2,000 the week before.
People are tested whether they have symptoms or not.
The study does not cover people staying in hospitals or care homes – only in the community.
Figures from the Covid symptom study app also suggest a growth in new cases since the end of August – the first time since mid-June there has been a significant rise in numbers.
However the virus is still at much lower levels than at the peak of the pandemic in April.
Katherine Kent, from the ONS infection survey, said the results suggested “an increase in Covid-19 infections in England during recent weeks with higher infection rates among 17-34 year olds”.
In Wales, the ONS estimates there was no increase in cases during the first week of September.
But in England, it estimates that 39,700 people were infected with the virus between 30 August and 5 September – 11,000 more than the previous week’s estimate.