The number of schools in England reporting partial closures due to suspected or confirmed coronavirus cases has quadrupled in a week, figures show.
State schools that weren't fully open on September 17 over Covid-19 rose to four per cent - up from one per cent on September 10, Department for Education (DfE) statistics suggest.
This could mean around 900 schools have sent pupils home.
Overall attendance has also dipped slightly from 88 per cent to 87pc - in usual times the average attendance for state schools is around 95 per cent.
This also means that over a million pupils weren't in school last Thursday - whether that be due to the virus or other reasons.
The latest data comes as education leaders have warned that children’s education has been disrupted as teachers and pupils have struggled to access tests to rule out Covid-19 since schools reopened this month.
One school leaders’ union said the latest figures should “ring alarm bells” about the “failure of Covid testing”.
Paul Whiteman, general secretary of the school leaders’ union NAHT, said: “The government would have been hoping to see attendance figures beginning to rise after the first week back, so the fact they have gone in the opposite direction should ring alarm bells.
“Clearly, the failure of Covid testing sits at the heart of this. The inability of staff and families to successfully get tested when they display symptoms means that schools are struggling with staffing, children are missing school, and ultimately that children’s education is being needlessly disrupted.
Get the latest updates from across Greater Manchester direct to your inbox with the free MEN newsletter
You can sign up very simply by following the instructions here
“If schools are to remain open during this second wave, tests need to be readily available for everyone so that those who get negative results can get back into school quickly.”
The DfE statistics, based on responses from 76 per cent of state schools, suggest that hardly any schools have completely closed with 99 per cent of state schools recorded as open on September 17. The 0.1 pc that were fully shut were due to Covid-related reasons.
In Greater Manchester, three schools have fully closed.
Horton Mill Primary School, in Glodwick, Oldham, had closed to all pupils after positive cases involving pupils and staff in several year groups.
St Luke's Primary in Heywood became the second to fully close amid a Covid outbreak on Friday.
Most recently, St Gilbert's RC Primary in Winton, Eccles, has been forced to close to every year group after positive Covid cases left just two teachers on site.
According to the data, a lower proportion of vulnerable children, such as those with a social worker or those with an education, health and care plan (EHCP), were in school, with an attendance rate of 81 per cent.
Kevin Courtney, joint general secretary of the National Education Union (NEU), said: “It is clear from the latest statistics that the government is failing in its duty to reduce the infection rate and to provide pupils and teachers with tests in a timely fashion.
“This is eroding trust among parents, and it will be an uphill struggle for it to be regained.”
The figures also show that more primary schools were fully open (95pc) than secondary schools (92pc)
Pupil attendance was lower in special schools (77pc) and alternative provision (56pc), the data suggests.
Education Secretary Gavin Williamson said: “As we would expect, this data shows a small number of pupils are self-isolating in line with public health advice, and schools, colleges and early years settings across the country continue to work tremendously hard to ensure protective measures are in place to reduce the risks of transmission.
“All have access to timely advice and support through our helpline if they have a positive case.
“The fact so many schools are open is testament to that hard work and, crucially, means children and young people can continue their education with minimal disruption.”