Around half of primary schools in England reopened to more children last week, new figures show.
According to the Department of Education, around 659,000 children were at school last Thursday, 6.9% of all pupils who normally attend.
In state-funded schools the rate was higher the national average at 11%.
This was the first week that schools in England began admitting children in nursery, Reception, Year 1 and Year 6 as part of a phased reopening as the coronavirus lockdown is eased.
This is an increase from 21 May, when approximately 244,000 (2.6%) were in school.
Schools have been shut in England since March because of the COVID-19 outbreak, although some remained open for vulnerable children and the children of key workers.
According to the Department for Education's figures, 52% of education settings that normally accept at least one of these year groups were open to more children on 4 June.
The release of the figures comes as the government is expected to scrap plans for all pupils in England to return to primary school this term before the summer holidays.
Education Secretary Gavin Williamson will make a statement in the Commons shortly in which he is set to confirm the news.
Guidance on class sizes - which limits them to 15 pupils - and social distancing will not be changed, government sources have said.
Some schools have said they are already full and cannot accommodate more children.
They have said they are limited by classroom sizes, inadequate staff numbers and the requirement to observe social distancing.
However, schools may be able to allow in additional pupils from other year groups if they are able to do so within the rules.
Reacting to the latest figures, Mr Williamson said: "It is encouraging to see the majority of primary schools open their doors to more pupils, and almost double the number of children now attending early years settings.
"This is still a difficult time for families and many feel anxious about their children going back - but I can reassure families, and those working in education settings, that the welfare of children and staff will continue to be at the heart of all our decisions.
"Families should also be reassured by the incredible work teachers and support staff are doing to adapt their settings and routines, while making sure schools and nurseries remain as welcoming as they have always been."